SlideShare a Scribd company logo
1 of 72
Limit of an Exponential
Function
Let a and b be real numbers,
where b > 0 and b ≠ 1.
Then,
𝐥𝐢𝐦
𝒙→𝒂
𝒃 𝒙
= 𝒃 𝒂
.
Properties
There are four basic properties in limits,
which are used as formulas in evaluating the
limits of exponential functions.
1.Power Rule
2.Constant Base Power Rule
3.Constant Exponent Power Rule
4.Radical Power Rule
1. Power Rule
𝒍𝒊𝒎
𝒙→𝒂
𝒇 𝒙 𝒈 𝒙
= 𝒍𝒊𝒎
𝒙→𝒂
𝒇 𝒙
𝒍𝒊𝒎
𝒙→𝒂
𝒈 𝒙
It is a property of power rule, used to
find the limit of an exponential function
whose base and exponent are in a
function form.
1. Power Rule 𝒍𝒊𝒎
𝒙→𝒂
𝒇 𝒙 𝒈 𝒙
= 𝒍𝒊𝒎
𝒙→𝒂
𝒇 𝒙
𝒍𝒊𝒎
𝒙→𝒂
𝒈 𝒙
Example: Evaluate 𝒇 𝒙 = 𝒙 𝟐 − 𝟒, 𝒈 𝒙 = 𝟐𝒙 ; 𝐥𝐢𝐦
𝒙→𝟑
𝒇 𝒙 𝒈 𝒙
Solution: 𝐥𝐢𝐦
𝒙→3
𝒇 𝒙 𝒈 𝒙
= 𝐥𝐢𝐦
𝒙→3
𝒇 𝒙
𝐥𝐢𝐦
𝒙→𝟑
𝒈 𝒙
= 𝐥𝐢𝐦
𝒙→3
𝒇 𝒙2
− 4
𝐥𝐢𝐦
𝒙→3
𝒈 2𝒙
= 𝟑 𝟐
− 𝟒
𝟐 𝟑
= 𝟗 − 𝟒 𝟔
= 𝟓 𝟔 = 𝟏𝟓, 𝟔𝟐𝟓
2. Constant Base Power Rule
𝒍𝒊𝒎
𝒙→𝒂
𝒃 𝒇 𝒙
= 𝒍𝒊𝒎
𝒙→𝒂
𝒃
𝒍𝒊𝒎
𝒙→𝒂
𝒇 𝒙
The limit of an exponential function is equal to
the limit of the exponent with same base. It is
called the limit rule of an exponential function.
2. Constant Base Power Rule
𝒍𝒊𝒎
𝒙→𝒂
𝒃 𝒇 𝒙
= 𝒍𝒊𝒎
𝒙→𝒂
𝒃
𝒍𝒊𝒎
𝒙→𝒂
𝒇 𝒙
Example:
Solution:
Evaluate 𝑏 = 12, 𝑓 𝑥 = 𝑥 + 3; 𝐥𝐢𝐦
𝒙→𝟏
𝒃 𝒇(𝒙)
𝒍𝒊𝒎
𝒙→𝟏
𝒃 )𝒇(𝒙
= 𝒍𝒊𝒎
𝒙→𝟏
𝟏𝟐 𝒙+𝟑
= 𝒍𝒊𝒎
𝒙→𝟏
𝟏𝟐
𝒍𝒊𝒎
𝒙→𝟏
𝒙+𝟑
= 𝟏𝟐 𝒙+𝟑
= 𝟏𝟐 𝟏+𝟑
= 𝟏𝟐 𝟒
= 𝟐𝟎, 𝟕𝟑𝟔
3. Constant Exponent Power Rule
𝒍𝒊𝒎
𝒙→𝒂
𝒇 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→𝒂
𝒇 𝒙 𝒏
Example:
Solution:
Evaluate 𝑓 𝑥 = 16𝑥2
− 64, 𝑛 = 2; 𝐥𝐢𝐦
𝒙→𝟏
𝒇 𝒙
𝒏
𝒍𝒊𝒎
𝒙→𝟏
𝒇 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→𝟏
𝒇 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→𝟏
𝟏𝟔𝒙 𝟐
− 𝟔𝟒
𝟐
= 𝟏𝟔 𝟏 𝟐
− 𝟔𝟒
𝟐
= 𝟏𝟔 − 𝟔𝟒 𝟐
= −𝟒𝟖 𝟐 = 𝟐, 𝟑𝟎𝟒
4. Radical Power Rule
𝒍𝒊𝒎
𝒙→𝒂
𝒏
)𝒇(𝒙 = 𝒏
𝒍𝒊𝒎
𝒙→𝒂
)𝒇(𝒙
Example:
Solution:
Evaluate 𝒇 𝒙 = 𝒙 𝟐
− 𝟔𝒙 + 𝟗, 𝒏 = 𝟐; 𝒍𝒊𝒎
𝒙→𝟔
𝒏
𝒇(𝒙)
𝒍𝒊𝒎
𝒙→𝟔
𝒏
)𝒇(𝒙 = 𝒏
𝒍𝒊𝒎
𝒙→𝟔
)𝒇(𝒙
= 𝐥𝐢𝐦
𝒙→6
𝒙2 − 6𝒙 + 9
= 𝒙 − 3 2 = 𝒙 − 3
= 6 − 3 = 𝟑
Let’s Practice!!!
1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟐𝟒𝒙 + 𝟑𝟔, 𝒏 = 𝟐;
a. 𝒍𝒊𝒎
𝒙→−𝟑
𝒏
𝒇(𝒙) b. 𝒍𝒊𝒎
𝒙→𝟒
𝒇 𝒙 𝒏
2. Evaluate 𝒇 𝒙 = 𝒙 𝟑
− 𝟐𝟕, 𝒈 𝒙 = 𝟐𝒙 + 𝟏
a. 𝒍𝒊𝒎
𝒙→𝟐
𝒇 𝒙 𝒈 𝒙
3. Evaluate 𝑏 = 𝟑, 𝑓 𝑥 = 𝒙 − 𝟒
a. 𝐥𝐢𝐦
𝒙→𝟖
𝒃 𝒇(𝒙)
1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟐𝟒𝒙 + 𝟑𝟔, 𝒏 = 𝟐;
a. 𝒍𝒊𝒎
𝒙→−𝟑
𝒏
𝒇(𝒙)
𝒍𝒊𝒎
𝒙→−𝟑
𝒏
)𝒇(𝒙 = 𝒏
𝒍𝒊𝒎
𝒙→−𝟑
)𝒇(𝒙
= 𝐥𝐢𝐦
𝒙→−𝟑
𝟒𝒙2 − 𝟐𝟒𝒙 + 𝟑𝟔
= 𝟐𝒙 − 𝟔 2 = 𝟐𝒙 − 𝟔
= 𝟐 −𝟑 − 𝟔
= −𝟏𝟐
= −𝟔 − 𝟔
1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟐𝟒𝒙 + 𝟑𝟔, 𝒏 = 𝟐;
b. 𝒍𝒊𝒎
𝒙→𝟒
𝒇 𝒙 𝒏
𝒍𝒊𝒎
𝒙→𝟒
𝒇 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→𝟒
𝒇 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→𝟒
𝟒𝒙 𝟐
− 𝟐𝟒𝒙 + 𝟑𝟔
𝟐
= 𝟒 𝟒 𝟐
− 𝟐𝟒 𝟒 + 𝟑𝟔
𝟐
= 𝟒 𝟏𝟔 − 𝟗𝟔 + 𝟑𝟔 𝟐
= 𝟒 𝟐
= 𝟏𝟔
= 𝟔𝟒 − 𝟗𝟔 + 𝟑𝟔 𝟐
2. Evaluate 𝒇 𝒙 = 𝒙 𝟑 − 𝟐𝟕, 𝒈 𝒙 = 𝟐𝒙 + 𝟏
a. 𝒍𝒊𝒎
𝒙→𝟐
𝒇 𝒙 𝒈 𝒙
𝐥𝐢𝐦
𝒙→𝟐
𝒇 𝒙 𝒈 𝒙
= 𝐥𝐢𝐦
𝒙→2
𝒇 𝒙
𝐥𝐢𝐦
𝒙→𝟐
𝒈 𝒙
= 𝐥𝐢𝐦
𝒙→𝟐
𝒙 𝟑
− 𝟐𝟕
𝐥𝐢𝐦
𝒙→𝟐
𝟐𝐱+𝟏
= 𝟐 𝟑
− 𝟐𝟕
𝟐 𝟐 +𝟏
= 𝟖 − 𝟐𝟕 𝟓
= −𝟏𝟗 𝟓
= −𝟐, 𝟒𝟕𝟔, 𝟎𝟗𝟗
3. Evaluate 𝑏 = 𝟑, 𝑓 𝑥 = 𝒙 − 𝟒
a. 𝐥𝐢𝐦
𝒙→𝟖
𝒃 𝒇(𝒙)
𝒍𝒊𝒎
𝒙→𝟖
𝒃 )𝒇(𝒙
= 𝒍𝒊𝒎
𝒙→𝟖
𝟑 𝒙−𝟒
= 𝒍𝒊𝒎
𝒙→𝟖
𝟑
𝒍𝒊𝒎
𝒙→𝟖
𝒙−𝟒
= 𝟑 𝒙−𝟒
= 𝟑 𝟖−𝟒
= 𝟑 𝟒
= 𝟖𝟏
Seatwork 3.1
1. Evaluate 𝒇 𝒙 = 𝒙 𝟐
+ 𝟏𝟔𝒙 + 𝟖, 𝒏 = 𝟑;
a. 𝒍𝒊𝒎
𝒙→𝟒
𝒏
𝒇(𝒙) b. 𝒍𝒊𝒎
𝒙→−𝟐
𝒇 𝒙 𝒏
2. Evaluate 𝒇 𝒙 = 𝒙 𝟐
− 𝟔𝟒, 𝒈 𝒙 = 𝒙 − 𝟓
a. 𝒍𝒊𝒎
𝒙→𝟗
𝒇 𝒙 𝒈 𝒙 b. 𝒍𝒊𝒎
𝒙→𝟗
𝒈 𝒙 𝒇 𝒙
3. Evaluate 𝑏 = 𝟏𝟓, 𝑓 𝑥 = 𝒙 𝟐 + 𝟐𝒙 + 𝟏
a. 𝐥𝐢𝐦
𝒙→𝟐
𝒃 𝒇(𝒙)
b. 𝐥𝐢𝐦
𝒙→−𝟑
𝒃 𝒇(𝒙)
ANSWERS
1. Evaluate 𝒇 𝒙 = 𝒙 𝟐
+ 𝟏𝟔𝒙 + 𝟖, 𝒏 = 𝟑;
a. 𝒍𝒊𝒎
𝒙→𝟒
𝒏
𝒇(𝒙)
𝒍𝒊𝒎
𝒙→𝟒
𝒏
)𝒇(𝒙 = 𝒏
𝒍𝒊𝒎
𝒙→𝟒
)𝒇(𝒙
=
𝟑
𝒍𝒊𝒎
𝒙→𝟒
𝒙 𝟐 + 𝟏𝟔𝒙 + 𝟖
=
3
𝟒 𝟐 + 𝟏𝟔 𝟒 + 𝟖
=
3
𝟏𝟔 + 𝟔𝟒 + 𝟖
= 𝟒. 𝟒𝟓
=
3
𝟖𝟖
1. Evaluate 𝒇 𝒙 = 𝒙 𝟐
+ 𝟏𝟔𝒙 + 𝟖, 𝒏 = 𝟑;
b. 𝒍𝒊𝒎
𝒙→−𝟐
𝒇 𝒙 𝒏
𝒍𝒊𝒎
𝒙→−𝟐
𝒇 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→−𝟐
𝒇 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→−𝟐
𝒙 𝟐
+ 𝟏𝟔𝒙 + 𝟖
𝟑
= −𝟐 𝟐
+ 𝟏𝟔 −𝟐 + 𝟖
𝟑
= 𝟏𝟔 − 𝟑𝟐 + 𝟖 𝟑
= −𝟖 𝟑
= −𝟓𝟏𝟐
2. Evaluate 𝒇 𝒙 = 𝒙 𝟐 − 𝟔𝟒, 𝒈 𝒙 = 𝒙 − 𝟓
a. 𝒍𝒊𝒎
𝒙→𝟗
𝒇 𝒙 𝒈 𝒙
𝐥𝐢𝐦
𝒙→𝟗
𝒇 𝒙 𝒈 𝒙
= 𝐥𝐢𝐦
𝒙→9
𝒇 𝒙
𝐥𝐢𝐦
𝒙→𝟗
𝒈 𝒙
= 𝐥𝐢𝐦
𝒙→𝟗
𝒙 𝟐
− 𝟔𝟒
𝐥𝐢𝐦
𝒙→𝟗
𝐱−𝟓
= 𝟗 𝟐
− 𝟔𝟒
𝟗−𝟓
= 𝟖𝟏 − 𝟔𝟒 𝟒
= 𝟏𝟕 𝟒
= 𝟖𝟑, 𝟓𝟐𝟏
2. Evaluate 𝒇 𝒙 = 𝒙 𝟐 − 𝟔𝟒, 𝒈 𝒙 = 𝒙 − 𝟓
b. 𝒍𝒊𝒎
𝒙→𝟗
𝒈 𝒙 𝒇 𝒙
𝐥𝐢𝐦
𝒙→𝟗
𝒈 𝒙 𝒇 𝒙
= 𝐥𝐢𝐦
𝒙→9
𝒈 𝒙
𝐥𝐢𝐦
𝒙→𝟗
𝒇 𝒙
= 𝐥𝐢𝐦
𝒙→𝟗
𝒙 − 𝟓
𝐥𝐢𝐦
𝒙→𝟗
𝐱 𝟐−𝟔𝟒
= (𝟗 − 𝟓) 𝟗 𝟐−𝟔𝟒
= (𝟒) 𝟖𝟏−𝟔𝟒
= 𝟒 𝟏𝟕
= 𝟏𝟕, 𝟏𝟕𝟗, 𝟖𝟔𝟗, 𝟏𝟖𝟒
3. Evaluate 𝑏 = 𝟏𝟓, 𝑓 𝑥 = 𝒙 𝟐 + 𝟐𝒙 + 𝟏
a. 𝐥𝐢𝐦
𝒙→𝟐
𝒃 𝒇(𝒙)
𝒍𝒊𝒎
𝒙→𝟐
𝒃 )𝒇(𝒙
= 𝒍𝒊𝒎
𝒙→𝟐
𝟏𝟓 𝒙 𝟐+𝟐𝒙+𝟏
= 𝒍𝒊𝒎
𝒙→𝟐
𝟏𝟓
𝒍𝒊𝒎
𝒙→𝟐
𝒙 𝟐+𝟐𝒙+𝟏
= 𝟏𝟓 𝒙 𝟐+𝟐𝒙+𝟏
= 𝟏𝟓 𝟐 𝟐+𝟐 𝟐 +𝟏
= 𝟏𝟓 𝟗
= 𝟑𝟖, 𝟒𝟒𝟑, 𝟑𝟓𝟗, 𝟑𝟕𝟓
3. Evaluate 𝑏 = 𝟏𝟓, 𝑓 𝑥 = 𝒙 𝟐 + 𝟐𝒙 + 𝟏
b. 𝐥𝐢𝐦
𝒙→−𝟑
𝒃 𝒇(𝒙)
𝒍𝒊𝒎
𝒙→−𝟑
𝒃 )𝒇(𝒙
= 𝒍𝒊𝒎
𝒙→−𝟑
𝟏𝟓 𝒙 𝟐+𝟐𝒙+𝟏
= 𝒍𝒊𝒎
𝒙→−𝟑
𝟏𝟓
𝒍𝒊𝒎
𝒙→−𝟑
𝒙 𝟐+𝟐𝒙+𝟏
= 𝟏𝟓 𝒙 𝟐+𝟐𝒙+𝟏
= 𝟏𝟓 −𝟑 𝟐+𝟐 −𝟑 +𝟏
= 𝟏𝟓 𝟒
= 𝟓𝟎, 𝟔𝟐𝟓
Quiz 3.1
Evaluate 𝒇 𝒙 = 𝟏𝟔𝒙 𝟐 − 𝟖𝒙 + 𝟏,
𝒈 𝒙 = 𝟔𝟒𝒙 𝟐 + 𝟒𝟖𝒙 + 𝟗,
𝒏 = 𝟐;
a. 𝒍𝒊𝒎
𝒙→𝟓
𝒏
𝒇(𝒙) b. 𝒍𝒊𝒎
𝒙→−𝟓
𝒇 𝒙 𝒏
c. 𝒍𝒊𝒎
𝒙→𝟖
𝒏
𝒈(𝒙) d. 𝒍𝒊𝒎
𝒙→−𝟖
𝒈 𝒙 𝒏
Evaluate 𝒇 𝒙 = 𝟗𝒛 𝟐 − 𝟏𝟎𝟎,
𝒈 𝒙 = 𝒛 𝟐
− 𝟐𝟓
a. 𝒍𝒊𝒎
𝒛→−𝟑
𝒇 𝒙 𝒈 𝒙 b. 𝒍𝒊𝒎
𝒛→𝟑
𝒈 𝒙 𝒇 𝒙
Evaluate 𝒃 = 𝟑𝟔, 𝒇 𝒙 = 𝒙 𝟑 − 𝟐𝟕
a. 𝐥𝐢𝐦
𝒙→𝟑
𝒃 𝒇(𝒙) b. 𝐥𝐢𝐦
𝒙→𝟐
𝒃 𝒇(𝒙)
ANSWERS
1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗,
𝒈 𝒙 = 𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒, 𝒏 = 𝟑;
a. 𝒍𝒊𝒎
𝒙→𝟑
𝒏
𝒇(𝒙)
𝒍𝒊𝒎
𝒙→𝟑
𝒏
)𝒇(𝒙 = 𝒏
𝒍𝒊𝒎
𝒙→𝟑
)𝒇(𝒙
=
𝟑
𝒍𝒊𝒎
𝒙→𝟑
𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗
=
3
𝟒 𝟑 𝟐 − 𝟔 𝟑 + 𝟗
=
3
𝟑𝟔 − 𝟏𝟖 + 𝟗 = 𝟑=
3
𝟐𝟕
1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗,
𝒈 𝒙 = 𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒, 𝒏 = 𝟑;
b. 𝒍𝒊𝒎
𝒙→−𝟑
𝒇 𝒙 𝒏
𝒍𝒊𝒎
𝒙→−𝟑
𝒇 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→−𝟑
𝒇 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→−𝟑
𝟒𝒙 𝟐
− 𝟔𝒙 + 𝟗
𝟑
= 𝟒 −𝟑 𝟐
− 𝟔 −𝟑 + 𝟗
𝟑
= 𝟑𝟔 + 𝟏𝟖 + 𝟗 𝟑
= 𝟔𝟑 𝟑
= 𝟐𝟓𝟎, 𝟎𝟒𝟕
1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗,
𝒈 𝒙 = 𝒙 𝟑
+ 𝟖𝒙 𝟐
− 𝟏𝟔𝒙 + 𝟒, 𝒏 = 𝟑;
c. 𝒍𝒊𝒎
𝒙→𝟐
𝒏
𝒈(𝒙)
𝒍𝒊𝒎
𝒙→𝟐
𝒏
)𝒈(𝒙 = 𝒏
𝒍𝒊𝒎
𝒙→𝟐
)𝒈(𝒙
=
𝟑
𝒍𝒊𝒎
𝒙→𝟐
𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒
=
3
𝟐 𝟑 + 𝟖 𝟐 𝟐 − 𝟏𝟔 𝟐 + 𝟒
=
3
𝟖 + 𝟑𝟐 − 𝟑𝟐 + 𝟒 = 𝟐. 𝟐𝟗=
3
𝟏𝟐
1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗,
𝒈 𝒙 = 𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒, 𝒏 = 𝟑;
d. 𝒍𝒊𝒎
𝒙→−𝟐
𝒈 𝒙 𝒏
𝒍𝒊𝒎
𝒙→−𝟐
𝒈 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→−𝟐
𝒈 𝒙 𝒏
= 𝒍𝒊𝒎
𝒙→−𝟐
𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒
𝟑
= −𝟐 𝟑
+ 𝟖 −𝟐 𝟐
− 𝟏𝟔 −𝟐 + 𝟒
𝟑
= −𝟖 + 𝟑𝟐 + 𝟑𝟐 + 𝟒 𝟑
= 𝟔𝟎 𝟑
= 𝟐𝟏𝟔, 𝟎𝟎𝟎
2. Evaluate 𝒇 𝒙 = 𝟏𝟔𝐱 𝟐 − 𝟐𝟓,
𝒈 𝒙 = 𝒙 𝟑
− 𝟏
a. 𝒍𝒊𝒎
𝒙→𝟑
𝒇 𝒙 𝒈 𝒙
𝐥𝐢𝐦
𝒙→𝟑
𝒇 𝒙 𝒈 𝒙
= 𝐥𝐢𝐦
𝒙→3
𝒇 𝒙
𝐥𝐢𝐦
𝒙→𝟑
𝒈 𝒙
= 𝐥𝐢𝐦
𝒙→𝟑
𝟏𝟔𝒙 𝟐
− 𝟐𝟓
𝐥𝐢𝐦
𝒙→𝟑
𝐱 𝟑−𝟏
= 𝟏𝟔 𝟑 𝟐
− 𝟐𝟓
𝟑 𝟑−𝟏
= 𝟏𝟒𝟒 − 𝟐𝟓 𝟐𝟔
= 𝟏𝟏𝟗 𝟐𝟔
= 𝟗. 𝟐𝟏 × 𝟏𝟎 𝟓𝟑
2. Evaluate 𝒇 𝒙 = 𝟏𝟔𝐱 𝟐 − 𝟐𝟓,
𝒈 𝒙 = 𝒙 𝟑
− 𝟏
b. 𝒍𝒊𝒎
𝒙→𝟑
𝒈 𝒙 𝒇 𝒙
𝐥𝐢𝐦
𝒙→𝟑
𝒈 𝒙 𝒇 𝒙
= 𝐥𝐢𝐦
𝒙→3
𝒈 𝒙
𝐥𝐢𝐦
𝒙→𝟑
𝒇 𝒙
= 𝐥𝐢𝐦
𝒙→𝟑
𝒙 𝟑
− 𝟏
𝐥𝐢𝐦
𝒙→𝟑
𝟏𝟔𝐱 𝟐−𝟐𝟓
= ( 𝟑 𝟑
− 𝟏) 𝟏𝟔(𝟑) 𝟐−𝟐𝟓
= (𝟐𝟔) 𝟏𝟒𝟒−𝟐𝟓
= 𝟐𝟔 𝟏𝟏𝟗
= 𝟐. 𝟒𝟏 × 𝟏𝟎 𝟏𝟔𝟖
3. Evaluate 𝑏 = 𝟐𝟒, 𝑓 𝑥 = 𝒙 𝟑 − 𝟖
a. 𝐥𝐢𝐦
𝒙→𝟑
𝒃 𝒇(𝒙)
𝒍𝒊𝒎
𝒙→𝟑
𝒃 )𝒇(𝒙
= 𝒍𝒊𝒎
𝒙→𝟑
𝟐𝟒 𝒙 𝟑−𝟖
= 𝒍𝒊𝒎
𝒙→𝟑
𝟐𝟒
𝒍𝒊𝒎
𝒙→𝟑
𝒙 𝟑−𝟖
= 𝟐𝟒 𝒙 𝟑−𝟖
= 𝟐𝟒 𝟑 𝟑−𝟖
= 𝟐𝟒 𝟏𝟗
= 𝟏. 𝟔𝟕 × 𝟏𝟎 𝟐𝟔
3. Evaluate 𝑏 = 𝟐𝟒, 𝑓 𝑥 = 𝒙 𝟑 − 𝟖
b. 𝐥𝐢𝐦
𝒙→𝟐
𝒃 𝒇(𝒙)
𝒍𝒊𝒎
𝒙→𝟐
𝒃 )𝒇(𝒙
= 𝒍𝒊𝒎
𝒙→𝟐
𝟐𝟒 𝒙 𝟑−𝟖
= 𝒍𝒊𝒎
𝒙→𝟐
𝟐𝟒
𝒍𝒊𝒎
𝒙→𝟐
𝒙 𝟑−𝟖
= 𝟐𝟒 𝒙 𝟑−𝟖
= 𝟐𝟒 𝟐 𝟑−𝟖
= 𝟐𝟒 𝟎
= 𝟏
Limit of Logarithmic
Function
Let a and b be real numbers,
where a > 0, b > 0 and b ≠ 1.
Then,
𝒍𝒊𝒎
𝒙→𝒂
( 𝒍𝒐𝒈 𝒃 𝒙) = 𝒍𝒐𝒈 𝒃 𝒂
Properties
There are three basic properties in limits,
which are used as formulas in evaluating the
limits of logarithmic functions.
1.Product Rule
2.Quotient Rule
3.Power Rule
1. Product Rule
Example:
Solution:
lim
𝑥→𝑎
(log 𝑏 𝐴𝐵) = lim
𝑥→𝑎
log 𝑏 𝐴 + log 𝑏 𝐵
Given 𝑨 = 𝒙 𝟐
+ 𝟐𝒙 + 𝟏, 𝑩 = 𝒙 − 𝟓, 𝒃 = 𝟓 𝒂𝒏𝒅 𝒙 = 𝟑,
find 𝒍𝒊𝒎
𝒙→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
𝒍𝒊𝒎
𝒙→𝒂
𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦
𝒙→𝟑
𝐥𝐨𝐠 𝟓(𝒙 𝟐
+𝟐𝒙 + 𝟏) + 𝐥𝐨𝐠 𝟓 𝒙 − 𝟓)
= 𝐥𝐨𝐠 𝟓 𝟑 𝟐
+ 𝟐 𝟑 + 𝟏 + 𝟑 − 𝟓
= 𝐥𝐨𝐠 𝟓 𝟗 + 𝟔 + 𝟏 − 𝟐
= 𝐥𝐨𝐠 𝟓 𝟏𝟒 = 𝟏. 𝟔𝟒
2. Quotient Rule
Example:
Solution:
lim
𝑥→𝑎
log 𝑏(
𝐴
𝐵
) = lim
𝑥→𝑎
log 𝑏 𝐴 − log 𝑏 𝐵
Given 𝑨 = 𝒙 𝟐 + 𝟐𝒙 + 𝟏, 𝑩 = 𝒙 − 𝟓, 𝒃 = 𝟓 𝒂𝒏𝒅 𝒙 = 𝟑,
find 𝒍𝒊𝒎
𝒙→𝒂
(𝒍𝒐𝒈 𝒃
𝑨
𝑩
)
𝒍𝒊𝒎
𝒙→𝒂
𝐥𝐨𝐠 𝒃
𝑨
𝑩
= 𝐥𝐢𝐦
𝒙→𝟑
𝐥𝐨𝐠 𝟓(𝒙 𝟐
+𝟐𝒙 + 𝟏) − 𝐥𝐨𝐠 𝟓 𝒙 − 𝟓)
= 𝐥𝐨𝐠 𝟓 𝟑 𝟐
+ 𝟐 𝟑 + 𝟏 − 𝟑 − 𝟓
= 𝐥𝐨𝐠 𝟓 𝟗 + 𝟔 + 𝟏 + 𝟐
= 𝐥𝐨𝐠 𝟓 𝟏𝟖 = 𝟏. 𝟕𝟗𝟔
3. Power Rule
Example:
Solution:
𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
= 𝒍𝒊𝒎
𝒙→𝒂
𝒏 𝒍𝒐𝒈 𝒃 𝑨
Given 𝑨 = 𝒙 − 𝟓, 𝒏 = 𝟑, 𝒃 = 𝟐 𝒂𝒏𝒅 𝒙 = 𝟖,
find 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
𝒍𝒊𝒎
𝒙→𝟖
𝒍𝒐𝒈 𝟐 𝒙 − 𝟓 𝟑
= 𝒍𝒊𝒎
𝒙→𝟖
𝟑 𝒍𝒐𝒈 𝟐 𝒙 − 𝟓
= 𝟑 𝒍𝒐𝒈 𝟐 𝟖 − 𝟓
= 𝟑 𝒍𝒐𝒈 𝟐 𝟑
= 𝟑 𝟏. 𝟓𝟖𝟓 = 𝟒. 𝟕𝟓𝟓
Let’s Practice!!!
1. Given 𝑨 = 𝒙 𝟐 + 𝟒𝒙 + 𝟒, 𝑩 = 𝒙 𝟐 − 𝟏𝟔,
𝒙 = 𝟐, 𝒃 = 𝟏𝟎, 𝒏 = 𝟒 ;
Find the following:
a. 𝒍𝒊𝒎
𝒙→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
b. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃(
𝑨
𝑩
)
c. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
Solution:
𝒍𝒊𝒎
𝒙→𝒂
𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦
𝒙→𝟐
𝐥𝐨𝐠 𝟏𝟎(𝒙 𝟐
+ 𝟒𝒙 + 𝟒) + 𝐥𝐨𝐠 𝟏𝟎(𝒙 𝟐
− 𝟏𝟔)
= 𝐥𝐨𝐠 𝟏𝟎 𝟐 𝟐
+ 𝟒 𝟐 + 𝟒 + 𝟐 𝟐
− 𝟏𝟔
= 𝐥𝐨𝐠 𝟏𝟎 𝟒 + 𝟖 + 𝟒 + 𝟒 − 𝟏𝟔
= 𝐥𝐨𝐠 𝟏𝟎 𝟒 = 𝟎. 𝟔𝟎𝟐
1. Given 𝑨 = 𝒙 𝟐 + 𝟒𝒙 + 𝟒, 𝑩 = 𝒙 𝟐 − 𝟏𝟔,
𝒙 = 𝟐, 𝒃 = 𝟏𝟎, 𝒏 = 𝟒 ;
Solution:
𝒍𝒊𝒎
𝒙→𝒂
𝐥𝐨𝐠 𝒃
𝑨
𝑩
= 𝐥𝐢𝐦
𝒙→𝟐
𝐥𝐨𝐠 𝟏𝟎 𝒙 𝟐
+ 𝟒𝒙 + 𝟒 − 𝐥𝐨𝐠 𝟏𝟎(𝒙 𝟐
− 𝟏𝟔)
1. Given 𝑨 = 𝒙 𝟐 + 𝟒𝒙 + 𝟒, 𝑩 = 𝒙 𝟐 − 𝟏𝟔,
𝒙 = 𝟐, 𝒃 = 𝟏𝟎, 𝒏 = 𝟒 ;
= 𝐥𝐨𝐠 𝟏𝟎 𝟐 𝟐
+ 𝟒 𝟐 + 𝟒 − 𝟐 𝟐
− 𝟏𝟔
= 𝐥𝐨𝐠 𝟏𝟎 𝟒 + 𝟖 + 𝟒 − 𝟒 + 𝟏𝟔
= 𝐥𝐨𝐠 𝟏𝟎 𝟐𝟖 = 𝟏. 𝟒𝟒𝟕
Solution:
𝒍𝒊𝒎
𝒙→𝟐
𝒍𝒐𝒈 𝟏𝟎 𝒙 𝟐
+ 𝟒𝒙 + 𝟒
𝟒
= 𝒍𝒊𝒎
𝒙→𝟐
𝟒 𝒍𝒐𝒈 𝟏𝟎 𝒙 𝟐
+ 𝟒𝒙 + 𝟒
= 𝟒 𝒍𝒐𝒈 𝟏𝟎 𝟐 𝟐
+ 𝟒 𝟐 + 𝟒
= 𝟒 𝒍𝒐𝒈 𝟏𝟎 𝟏𝟔
= 𝟒 𝟏. 𝟐𝟎𝟒 = 𝟒. 𝟖𝟏𝟔
1. Given 𝑨 = 𝒙 𝟐 + 𝟒𝒙 + 𝟒, 𝑩 = 𝒙 𝟐 − 𝟏𝟔,
𝒙 = 𝟐, 𝒃 = 𝟏𝟎, 𝒏 = 𝟒 ;
Seatwork 3.2
1. Given 𝑨 = 𝟗𝒙 𝟐
+ 𝟑𝟎𝒙 + 𝟐𝟓, 𝑩 = 𝟒𝒙 𝟐
− 𝟏𝟔,
𝒙 = 𝟓, 𝒃 = 𝟑𝟓, 𝒏 = 𝟏𝟓 ;
2. Given 𝑨 = 𝒙 𝟐
− 𝟏𝟔𝒙 + 𝟔𝟒, 𝑩 = 𝒙 𝟐
− 𝟏,
𝒙 = 𝟑, 𝒃 = 𝟐𝟓, 𝒏 = 𝟐𝟓
Find the following:
a. 𝒍𝒊𝒎
𝒙→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
b. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃(
𝑨
𝑩
)
c. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
2. Given 𝑨 = 𝒙 𝟐 + 𝟐𝟎𝒙 − 𝟏𝟎𝟎, 𝑩 = 𝒙 𝟐 − 𝟑𝟔,
𝒙 = 𝟏𝟐, 𝒃 = 𝟑𝟔, 𝒏 = 𝟐𝟓 ;
Find the following:
a. 𝒍𝒊𝒎
𝒙→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
b. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃(
𝑨
𝑩
)
c. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
ANSWERS
Solution:
𝒍𝒊𝒎
𝒙→𝒂
𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦
𝒙→𝟐
𝐥𝐨𝐠 𝟏𝟓(𝟐𝟓𝒙 𝟐
+ 𝟒𝟎𝒙 + 𝟏𝟔) + 𝐥𝐨𝐠 𝟏𝟓(𝒙 𝟐
− 𝟔𝟒)
= 𝐥𝐨𝐠 𝟏𝟓 𝟐𝟓 𝟐 𝟐
+ 𝟒𝟎 𝟐 + 𝟏𝟔 + 𝟐 𝟐
− 𝟔𝟒
= 𝐥𝐨𝐠 𝟏𝟓 𝟏𝟎𝟎 + 𝟖𝟎 + 𝟏𝟔 + 𝟒 − 𝟔𝟒
= 𝐥𝐨𝐠 𝟏𝟓 𝟏𝟑𝟔 = 𝟏. 𝟖𝟏𝟒
1. Given 𝑨 = 𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔, 𝑩 = 𝒙 𝟐 − 𝟔𝟒,
𝒙 = 𝟐, 𝒃 = 𝟏𝟓, 𝒏 = 𝟓 ;
Solution:
𝒍𝒊𝒎
𝒙→𝒂
𝐥𝐨𝐠 𝒃
𝑨
𝑩
= 𝐥𝐢𝐦
𝒙→𝟐
𝐥𝐨𝐠 𝟏𝟓 𝟐𝟓𝒙 𝟐
+ 𝟒𝟎𝒙 + 𝟏𝟔 − 𝐥𝐨𝐠 𝟏𝟓(𝒙 𝟐
− 𝟔𝟒)
1. Given 𝑨 = 𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔, 𝑩 = 𝒙 𝟐 − 𝟔𝟒,
𝒙 = 𝟐, 𝒃 = 𝟏𝟓, 𝒏 = 𝟓 ;
= 𝐥𝐨𝐠 𝟏𝟓 𝟐𝟓 𝟐 𝟐
+ 𝟒𝟎 𝟐 + 𝟏𝟔 − 𝟐 𝟐
− 𝟔𝟒
= 𝐥𝐨𝐠 𝟏𝟓 𝟏𝟎𝟎 + 𝟖𝟎 + 𝟏𝟔 − 𝟒 + 𝟔𝟒
= 𝐥𝐨𝐠 𝟏𝟓 𝟐𝟓𝟔 = 𝟐. 𝟎𝟒𝟖
Solution:
𝒍𝒊𝒎
𝒙→𝟐
𝒍𝒐𝒈 𝟏𝟓 𝟐𝟓𝒙 𝟐
+ 𝟒𝟎𝒙 + 𝟏𝟔
𝟓
= 𝒍𝒊𝒎
𝒙→𝟐
𝟓 𝒍𝒐𝒈 𝟏𝟓 𝟐𝟓𝒙 𝟐
+ 𝟒𝟎𝒙 + 𝟏𝟔
= 𝟓 𝒍𝒐𝒈 𝟏𝟓 𝟐𝟓 𝟐 𝟐
+ 𝟒𝟎 𝟐 + 𝟏𝟔
= 𝟓 𝒍𝒐𝒈 𝟏𝟓 𝟏𝟗𝟔
= 𝟓 𝟏. 𝟗𝟒𝟗 = 𝟗. 𝟕𝟒𝟓
1. Given 𝑨 = 𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔, 𝑩 = 𝒙 𝟐 − 𝟔𝟒,
𝒙 = 𝟐, 𝒃 = 𝟏𝟓, 𝒏 = 𝟓 ;
Solution:
𝒍𝒊𝒎
𝒙→𝒂
𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦
𝒙→𝟏𝟐
𝐥𝐨𝐠 𝟑𝟔(𝒙 𝟐
+ 𝟐𝟎𝒙 − 𝟏𝟎𝟎) + 𝐥𝐨𝐠 𝟑𝟔(𝒙 𝟐
− 𝟑𝟔)
= 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟐 𝟐
+ 𝟐𝟎 𝟏𝟐 − 𝟏𝟎𝟎 + 𝟏𝟐 𝟐
− 𝟑𝟔
= 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟒𝟒 + 𝟐𝟒𝟎 − 𝟏𝟎𝟎 + 𝟏𝟒𝟒 − 𝟑𝟔
= 𝐥𝐨𝐠 𝟑𝟔 𝟑𝟗𝟐 = 𝟏. 𝟔𝟔𝟔
2. Given 𝑨 = 𝒙 𝟐
+ 𝟐𝟎𝒙 − 𝟏𝟎𝟎, 𝑩 = 𝒙 𝟐
− 𝟑𝟔,
𝒙 = 𝟏𝟐, 𝒃 = 𝟑𝟔, 𝒏 = 𝟐𝟓 ;
Solution:
𝒍𝒊𝒎
𝒙→𝒂
𝐥𝐨𝐠 𝒃
𝑨
𝑩
= 𝐥𝐢𝐦
𝒙→𝟏𝟐
𝐥𝐨𝐠 𝟑𝟔 𝒙 𝟐
+ 𝟐𝟎𝒙 − 𝟏𝟎𝟎 − 𝐥𝐨𝐠 𝟑𝟔(𝒙 𝟐
− 𝟑𝟔)
2. Given 𝑨 = 𝒙 𝟐
+ 𝟐𝟎𝒙 − 𝟏𝟎𝟎, 𝑩 = 𝒙 𝟐
− 𝟑𝟔,
𝒙 = 𝟏𝟐, 𝒃 = 𝟑𝟔, 𝒏 = 𝟐𝟓 ;
= 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟐 𝟐
+ 𝟐𝟎 𝟏𝟐 − 𝟏𝟎𝟎 − 𝟏𝟐 𝟐
− 𝟑𝟔
= 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟒𝟒 + 𝟐𝟒𝟎 − 𝟏𝟎𝟎 − 𝟏𝟒𝟒 + 𝟑𝟔
= 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟕𝟔 = 𝟏. 𝟒𝟒𝟑
Solution:
𝒍𝒊𝒎
𝒙→𝟏𝟐
𝒍𝒐𝒈 𝟑𝟔 𝒙 𝟐
+ 𝟐𝟎𝒙 − 𝟏𝟎𝟎
𝟐𝟓
= 𝒍𝒊𝒎
𝒙→𝟏𝟐
𝟐𝟓 𝒍𝒐𝒈 𝟑𝟔 𝒙 𝟐
+ 𝟐𝟎𝒙 − 𝟏𝟎𝟎
= 𝟐𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟏𝟐 𝟐
+ 𝟐𝟎 𝟏𝟐 − 𝟏𝟎𝟎
= 𝟐𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟐𝟖𝟒
= 𝟐𝟓 𝟏. 𝟓𝟕𝟔 = 𝟑𝟗. 𝟒𝟎𝟗
2. Given 𝑨 = 𝒙 𝟐
+ 𝟐𝟎𝒙 − 𝟏𝟎𝟎, 𝑩 = 𝒙 𝟐
− 𝟑𝟔,
𝒙 = 𝟏𝟐, 𝒃 = 𝟑𝟔, 𝒏 = 𝟐𝟓 ;
Quiz 3.2
Given 𝑨 = 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒, 𝑩 = 𝒚 𝟐 − 𝟔𝟒,
𝒚 = 𝟓, 𝒃 = 𝟐𝟓, 𝒏 = 𝟖 ;
Find the following:
a. 𝒍𝒊𝒎
𝒙→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
b. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃(
𝑨
𝑩
)
c. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
Given 𝑨 = 𝟒𝟓𝒎 𝟐
− 𝟑𝟔𝒎 − 𝟗, 𝑩 = 𝒎 𝟐
− 𝟐𝒎 + 𝟐,
𝒎 = 𝟔, 𝒃 = 𝟑𝟔, 𝒏 = 𝟓 ;
Find the following:
a. 𝒍𝒊𝒎
𝒙→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
b. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃(
𝑨
𝑩
)
c. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
Given 𝑨 = 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔, 𝑩 = 𝒚 𝟑 − 𝟏,
𝒚 = 𝟑, 𝒃 = 𝟏𝟖, 𝒏 = 𝟔 ;
Find the following:
a. 𝒍𝒊𝒎
𝒙→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
b. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃(
𝑨
𝑩
)
c. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
ANSWERS
Solution:
𝒍𝒊𝒎
𝐲→𝒂
𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦
𝐲→𝟓
𝐥𝐨𝐠 𝟐𝟓(𝟑𝟔𝒚 𝟐
− 𝟗𝟔𝒚 + 𝟔𝟒) + 𝐥𝐨𝐠 𝟐𝟓(𝒚 𝟐
− 𝟔𝟒)
= 𝐥𝐨𝐠 𝟐𝟓 𝟑𝟔 𝟓 𝟐
− 𝟗𝟔 𝟓 + 𝟔𝟒 + 𝟓 𝟐
− 𝟔𝟒
= 𝐥𝐨𝐠 𝟐𝟓 𝟗𝟎𝟎 − 𝟒𝟖𝟎 + 𝟔𝟒 + 𝟐𝟓 − 𝟔𝟒
= 𝐥𝐨𝐠 𝟐𝟓 𝟒𝟒𝟓 = 𝟏. 𝟖𝟗𝟒
1. Given 𝑨 = 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒, 𝑩 = 𝒚 𝟐 − 𝟔𝟒,
𝒚 = 𝟓, 𝒃 = 𝟐𝟓, 𝒏 = 𝟖
Solution:
= 𝟏. 𝟗𝟒𝟓
1. Given 𝑨 = 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒, 𝑩 = 𝒚 𝟐 − 𝟔𝟒,
𝒚 = 𝟓, 𝒃 = 𝟐𝟓, 𝒏 = 𝟖
𝒍𝒊𝒎
𝐲→𝒂
𝐥𝐨𝐠 𝒃
𝑨
𝑩
= 𝐥𝐢𝐦
𝐲→𝟓
𝐥𝐨𝐠 𝟐𝟓 𝟑𝟔𝒚 𝟐
− 𝟗𝟔𝒚 + 𝟔𝟒 − 𝐥𝐨𝐠 𝟐𝟓(𝒚 𝟐
− 𝟔𝟒)
= 𝐥𝐨𝐠 𝟐𝟓 𝟑𝟔 𝟓 𝟐
− 𝟗𝟔 𝟓 + 𝟔𝟒 − 𝟓 𝟐
− 𝟔𝟒
= 𝐥𝐨𝐠 𝟐𝟓 𝟗𝟎𝟎 − 𝟒𝟖𝟎 + 𝟔𝟒 − 𝟐𝟓 + 𝟔𝟒
= 𝐥𝐨𝐠 𝟐𝟓 𝟓𝟐𝟑
Solution:
𝒍𝒊𝒎
𝒚→𝟓
𝒍𝒐𝒈 𝟐𝟓 𝟑𝟔𝒚 𝟐
− 𝟗𝟔𝒚 + 𝟔𝟒
𝟖
= 𝒍𝒊𝒎
𝒚→𝟓
𝟖 𝒍𝒐𝒈 𝟐𝟓 𝟑𝟔𝒚 𝟐
− 𝟗𝟔𝒚 + 𝟔𝟒
= 𝟖 𝒍𝒐𝒈 𝟐𝟓 𝟑𝟔 𝟓 𝟐
− 𝟗𝟔 𝟓 + +𝟔𝟒
= 𝟖 𝒍𝒐𝒈 𝟐𝟓 𝟒𝟖𝟒
= 𝟖 𝟏. 𝟗𝟐𝟏 = 𝟏𝟓. 𝟑𝟔𝟓
1. Given 𝑨 = 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒, 𝑩 = 𝒚 𝟐 − 𝟔𝟒,
𝒚 = 𝟓, 𝒃 = 𝟐𝟓, 𝒏 = 𝟖
Solution:
𝒍𝒊𝒎
𝐦→𝒂
𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦
𝐦→𝟔
𝐥𝐨𝐠 𝟑𝟔(𝟒𝟓𝒎 𝟐
− 𝟑𝟔𝒎 − 𝟗) + 𝐥𝐨𝐠 𝟑𝟔(𝒎 𝟐
− 𝟐𝒎 + 𝟐)
= 𝐥𝐨𝐠 𝟑𝟔 𝟒𝟓 𝟔 𝟐
− 𝟑𝟔 𝟔 − 𝟗 + 𝟔 𝟐
− 𝟐 𝟔 + 𝟐
= 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟔𝟐𝟎 − 𝟐𝟏𝟔 − 𝟗 + 𝟑𝟔 − 𝟏𝟐 + 𝟐
= 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟒𝟐𝟏 = 𝟐. 𝟎𝟐𝟔
2. Given 𝑨 = 𝟒𝟓𝒎 𝟐
− 𝟑𝟔𝒎 − 𝟗, 𝑩 = 𝒎 𝟐
− 𝟐𝒎 + 𝟐,
𝒎 = 𝟔, 𝒃 = 𝟑𝟔, 𝒏 = 𝟓 ;
Solution:
= 𝟐. 𝟎𝟏𝟓
2. Given 𝑨 = 𝟒𝟓𝒎 𝟐
− 𝟑𝟔𝒎 − 𝟗, 𝑩 = 𝒎 𝟐
− 𝟐𝒎 + 𝟐,
𝒎 = 𝟔, 𝒃 = 𝟑𝟔, 𝒏 = 𝟓 ;
𝒍𝒊𝒎
𝐦→𝒂
𝐥𝐨𝐠 𝒃
𝑨
𝑩
= 𝐥𝐢𝐦
𝐦→𝟔
𝐥𝐨𝐠 𝟑𝟔 𝟒𝟓𝒎 𝟐
− 𝟑𝟔𝒎 − 𝟗 − 𝐥𝐨𝐠 𝟑𝟔(𝒎 𝟐
− 𝟐𝒎 + 𝟐)
= 𝐥𝐨𝐠 𝟑𝟔 𝟒𝟓 𝟔 𝟐
− 𝟑𝟔 𝟔 − 𝟗 − 𝟔 𝟐
− 𝟐 𝟔 + 𝟐
= 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟔𝟐𝟎 − 𝟐𝟏𝟔 − 𝟗 − 𝟑𝟔 + 𝟏𝟐 − 𝟐
= 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟑𝟔𝟗
Solution:
𝒍𝒊𝒎
𝒎→𝟔
𝒍𝒐𝒈 𝟑𝟔 𝟒𝟓𝒎 𝟐
− 𝟑𝟔𝒎 − 𝟗
𝟓
= 𝒍𝒊𝒎
𝒙→𝟐
𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟒𝟓𝒎 𝟐
− 𝟑𝟔𝒎 − 𝟗
= 𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟒𝟓 𝟔 𝟐
− 𝟑𝟔 𝟔 − 𝟗
= 𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟏𝟑𝟗𝟓
= 𝟓 𝟐. 𝟎𝟐𝟏 = 𝟏𝟎. 𝟏𝟎𝟑
2. Given 𝑨 = 𝟒𝟓𝒎 𝟐
− 𝟑𝟔𝒎 − 𝟗, 𝑩 = 𝒎 𝟐
− 𝟐𝒎 + 𝟐,
𝒎 = 𝟔, 𝒃 = 𝟑𝟔, 𝒏 = 𝟓 ;
Solution:
𝒍𝒊𝒎
𝐲→𝒂
𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦
𝒚→𝟑
𝐥𝐨𝐠 𝟏𝟖(𝟏𝟔𝒚 𝟐
− 𝟒𝟔𝒚 + 𝟑𝟔) + 𝐥𝐨𝐠 𝟏𝟖(𝒚 𝟑
− 𝟏)
= 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟔 𝟑 𝟐
− 𝟒𝟖 𝟑 + 𝟑𝟔 + 𝟑 𝟑
− 𝟏
= 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟒𝟒 − 𝟏𝟒𝟒 + 𝟑𝟔 + 𝟐𝟕 − 𝟏
= 𝐥𝐨𝐠 𝟏𝟖 𝟔𝟐 = 𝟏. 𝟒𝟐𝟖
3. Given 𝑨 = 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔, 𝑩 = 𝒚 𝟑 − 𝟏,
𝒚 = 𝟑, 𝒃 = 𝟏𝟖, 𝒏 = 𝟔 ;
Solution:
= 𝟎. 𝟕𝟗𝟕
3. Given 𝑨 = 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔, 𝑩 = 𝒚 𝟑 − 𝟏,
𝒚 = 𝟑, 𝒃 = 𝟏𝟖, 𝒏 = 𝟔 ;
𝒍𝒊𝒎
𝐲→𝒂
𝐥𝐨𝐠 𝒃
𝑨
𝑩
= 𝐥𝐢𝐦
𝒚→𝟑
𝐥𝐨𝐠 𝟏𝟖 𝟏𝟔𝒚 𝟐
− 𝟒𝟔𝒚 + 𝟑𝟔 − 𝐥𝐨𝐠 𝟏𝟖(𝒚 𝟑
− 𝟏)
= 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟔 𝟑 𝟐
− 𝟒𝟖 𝟑 + 𝟑𝟔 − 𝟑 𝟐
− 𝟏
= 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟒𝟒 − 𝟏𝟒𝟒 + 𝟑𝟔 − 𝟐𝟕 + 𝟏
= 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟎
Solution:
𝒍𝒊𝒎
𝒚→𝟑
𝒍𝒐𝒈 𝟏𝟖 𝟏𝟔𝒚 𝟐
− 𝟒𝟖𝒚 + 𝟑𝟔
𝟔
= 𝒍𝒊𝒎
𝒚→𝟑
𝟔 𝒍𝒐𝒈 𝟏𝟖 𝟏𝟔𝒚 𝟐
− 𝟒𝟖𝒚 + 𝟑𝟔
= 𝟔 𝒍𝒐𝒈 𝟏𝟖 𝟏𝟔 𝟑 𝟐
− 𝟒𝟖 𝟑 + 𝟑𝟔
= 𝟔 𝒍𝒐𝒈 𝟏𝟖 𝟑𝟔
= 𝟔 𝟏. 𝟐𝟒𝟎 = 𝟕. 𝟒𝟑𝟗
3. Given 𝑨 = 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔, 𝑩 = 𝒚 𝟑 − 𝟏,
𝒚 = 𝟑, 𝒃 = 𝟏𝟖, 𝒏 = 𝟔 ;
Pointers to Review
Limits of Non – Algebraic Functions
Limit of an Exponential Function
Limit of Logarithmic Function
Given 𝑨 = 𝒚 𝟐 + 𝟔𝒚 + 𝟗, 𝑩 = 𝟒𝒚 𝟐 − 𝟏,
𝒚 = 𝟖, 𝒃 = 𝟏𝟓, 𝒏 = 𝟔 ;
Find the following:
a. 𝒍𝒊𝒎
𝒚→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
b. 𝒍𝒊𝒎
𝒚→𝒂
𝒍𝒐𝒈 𝒃(
𝑨
𝑩
)
c. 𝒍𝒊𝒎
𝒚→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
Given 𝑨 = 𝟑𝒙 𝟐 + 𝟗𝒙 + 𝟗, 𝑩 = 𝒙 − 𝟓,
𝒙 = 𝟐, 𝒃 = 𝟏𝟑, 𝒏 = 𝟏𝟎 ;
Find the following:
a. 𝒍𝒊𝒎
𝒙→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
b. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃(
𝑨
𝑩
)
c. 𝒍𝒊𝒎
𝒙→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏
Given 𝑨 = 𝟔𝒛 𝟐 − 𝟒𝒛 + 𝟓, 𝑩 = 𝟐𝒛 𝟐 + 𝟒𝒛 − 𝟑,
𝒛 = 𝟑, 𝒃 = 𝟖, 𝒏 = 𝟐;
Find the following:
a. 𝒍𝒊𝒎
𝒛→𝒂
(𝒍𝒐𝒈 𝒃 𝑨𝑩)
b. 𝒍𝒊𝒎
𝒛→𝒂
𝒍𝒐𝒈 𝒃(
𝑨
𝑩
)
c. 𝒍𝒊𝒎
𝒛→𝒂
𝒍𝒐𝒈 𝒃 𝑨 𝒏

More Related Content

What's hot

Rational Functions, Equations, and Inequalities.pptx
Rational Functions, Equations, and Inequalities.pptxRational Functions, Equations, and Inequalities.pptx
Rational Functions, Equations, and Inequalities.pptx
Johnlery Guzman
 
Operations on Functions
Operations on FunctionsOperations on Functions
Operations on Functions
swartzje
 

What's hot (20)

Evaluating functions basic rules
Evaluating functions   basic rulesEvaluating functions   basic rules
Evaluating functions basic rules
 
Lesson 13: Exponential and Logarithmic Functions (slides)
Lesson 13: Exponential and Logarithmic Functions (slides)Lesson 13: Exponential and Logarithmic Functions (slides)
Lesson 13: Exponential and Logarithmic Functions (slides)
 
General Mathematics - Composition of Functions
General Mathematics - Composition of FunctionsGeneral Mathematics - Composition of Functions
General Mathematics - Composition of Functions
 
Chapter 1 random variables and probability distributions
Chapter 1   random variables and probability distributionsChapter 1   random variables and probability distributions
Chapter 1 random variables and probability distributions
 
Lesson 14: Exponential Functions
Lesson 14: Exponential FunctionsLesson 14: Exponential Functions
Lesson 14: Exponential Functions
 
PHILOSOPHY - INTRODUCTION
PHILOSOPHY - INTRODUCTIONPHILOSOPHY - INTRODUCTION
PHILOSOPHY - INTRODUCTION
 
Rational Functions, Equations, and Inequalities.pptx
Rational Functions, Equations, and Inequalities.pptxRational Functions, Equations, and Inequalities.pptx
Rational Functions, Equations, and Inequalities.pptx
 
Mirror equation
Mirror equationMirror equation
Mirror equation
 
Higher order derivatives
Higher order derivativesHigher order derivatives
Higher order derivatives
 
Exponential Equation & Inequalities.pptx
Exponential Equation & Inequalities.pptxExponential Equation & Inequalities.pptx
Exponential Equation & Inequalities.pptx
 
Human actions that speed up landslides
Human actions that speed up landslidesHuman actions that speed up landslides
Human actions that speed up landslides
 
Representing Real-Life Situations Using Rational Function
Representing Real-Life Situations Using Rational FunctionRepresenting Real-Life Situations Using Rational Function
Representing Real-Life Situations Using Rational Function
 
Module 2 polynomial functions
Module 2   polynomial functionsModule 2   polynomial functions
Module 2 polynomial functions
 
Basic concept of Hazards
Basic concept of HazardsBasic concept of Hazards
Basic concept of Hazards
 
Chapter 2: Rational Function
Chapter 2: Rational FunctionChapter 2: Rational Function
Chapter 2: Rational Function
 
Conjunction And Disjunction
 Conjunction And Disjunction Conjunction And Disjunction
Conjunction And Disjunction
 
Operations on Functions
Operations on FunctionsOperations on Functions
Operations on Functions
 
Functional Notations
Functional NotationsFunctional Notations
Functional Notations
 
Evaluating Functions
Evaluating FunctionsEvaluating Functions
Evaluating Functions
 
One-to-one Functions.pptx
One-to-one Functions.pptxOne-to-one Functions.pptx
One-to-one Functions.pptx
 

Similar to Basic Calculus Lesson 3

Thai new testament-world_bible
Thai new testament-world_bibleThai new testament-world_bible
Thai new testament-world_bible
WorldBibles
 
Thai new testament-world_bible
Thai new testament-world_bibleThai new testament-world_bible
Thai new testament-world_bible
WorldBibles
 
หนังสือพิมพ์งานพระราชทานเพลิงศพ สมเด็จพระพุฒโฆษาจารย์
หนังสือพิมพ์งานพระราชทานเพลิงศพ สมเด็จพระพุฒโฆษาจารย์หนังสือพิมพ์งานพระราชทานเพลิงศพ สมเด็จพระพุฒโฆษาจารย์
หนังสือพิมพ์งานพระราชทานเพลิงศพ สมเด็จพระพุฒโฆษาจารย์
หนุ่มน้อย ดาร์จีลิ่ง
 

Similar to Basic Calculus Lesson 3 (9)

Math 8 Lesson 3 - 2nd Quarter
Math 8 Lesson 3 - 2nd QuarterMath 8 Lesson 3 - 2nd Quarter
Math 8 Lesson 3 - 2nd Quarter
 
6 DOF Rigid Body Equation of Motion 1
6 DOF Rigid Body Equation of Motion 16 DOF Rigid Body Equation of Motion 1
6 DOF Rigid Body Equation of Motion 1
 
6 DOF Rigid Body Equation of Motion 3
6 DOF Rigid Body Equation of Motion 36 DOF Rigid Body Equation of Motion 3
6 DOF Rigid Body Equation of Motion 3
 
Thai new testament-world_bible
Thai new testament-world_bibleThai new testament-world_bible
Thai new testament-world_bible
 
ေဒါက္တာလွေဘ တရုတ္ႏိုင္ငံသြားေန႕စဥ္မွတ္စာတမ္း 2
ေဒါက္တာလွေဘ တရုတ္ႏိုင္ငံသြားေန႕စဥ္မွတ္စာတမ္း 2ေဒါက္တာလွေဘ တရုတ္ႏိုင္ငံသြားေန႕စဥ္မွတ္စာတမ္း 2
ေဒါက္တာလွေဘ တရုတ္ႏိုင္ငံသြားေန႕စဥ္မွတ္စာတမ္း 2
 
Thai new testament-world_bible
Thai new testament-world_bibleThai new testament-world_bible
Thai new testament-world_bible
 
1 14
1 141 14
1 14
 
Math20160415 epsilondelta
Math20160415 epsilondeltaMath20160415 epsilondelta
Math20160415 epsilondelta
 
หนังสือพิมพ์งานพระราชทานเพลิงศพ สมเด็จพระพุฒโฆษาจารย์
หนังสือพิมพ์งานพระราชทานเพลิงศพ สมเด็จพระพุฒโฆษาจารย์หนังสือพิมพ์งานพระราชทานเพลิงศพ สมเด็จพระพุฒโฆษาจารย์
หนังสือพิมพ์งานพระราชทานเพลิงศพ สมเด็จพระพุฒโฆษาจารย์
 

More from alicelagajino

More from alicelagajino (20)

TLE 7 Lesson 5 - 2nd Quarter
TLE 7 Lesson 5 - 2nd QuarterTLE 7 Lesson 5 - 2nd Quarter
TLE 7 Lesson 5 - 2nd Quarter
 
TLE 7 Lesson 4 - 2nd Quarter
TLE 7 Lesson 4 - 2nd QuarterTLE 7 Lesson 4 - 2nd Quarter
TLE 7 Lesson 4 - 2nd Quarter
 
TLE 7 Lesson 3 - 2nd Quarter
TLE 7 Lesson 3 - 2nd QuarterTLE 7 Lesson 3 - 2nd Quarter
TLE 7 Lesson 3 - 2nd Quarter
 
TLE 7 Lesson 2 - 2nd Quarter
TLE 7 Lesson 2 - 2nd QuarterTLE 7 Lesson 2 - 2nd Quarter
TLE 7 Lesson 2 - 2nd Quarter
 
TLE 7 Lesson 1 - 2nd Quarter
TLE 7 Lesson 1 - 2nd QuarterTLE 7 Lesson 1 - 2nd Quarter
TLE 7 Lesson 1 - 2nd Quarter
 
TLE 7 Lesson 6 - 1st Quarter
TLE 7 Lesson 6 - 1st QuarterTLE 7 Lesson 6 - 1st Quarter
TLE 7 Lesson 6 - 1st Quarter
 
TLE 7 Lesson 5 - 1st Quarter
TLE 7 Lesson 5 - 1st QuarterTLE 7 Lesson 5 - 1st Quarter
TLE 7 Lesson 5 - 1st Quarter
 
TLE 7 Lesson 4 - 1st Quarter
TLE 7 Lesson 4 - 1st QuarterTLE 7 Lesson 4 - 1st Quarter
TLE 7 Lesson 4 - 1st Quarter
 
TLE 7 Lesson 3 - 1st Quarter
TLE 7 Lesson 3 - 1st QuarterTLE 7 Lesson 3 - 1st Quarter
TLE 7 Lesson 3 - 1st Quarter
 
TLE 7 Lesson 2 - 1st Quarter
TLE 7 Lesson 2 - 1st QuarterTLE 7 Lesson 2 - 1st Quarter
TLE 7 Lesson 2 - 1st Quarter
 
TLE 7 Lesson 1 - 1st Quarter
TLE 7 Lesson 1 - 1st QuarterTLE 7 Lesson 1 - 1st Quarter
TLE 7 Lesson 1 - 1st Quarter
 
Math 8 Lesson 2 - 2nd Quarter
Math 8 Lesson 2 - 2nd QuarterMath 8 Lesson 2 - 2nd Quarter
Math 8 Lesson 2 - 2nd Quarter
 
Math 8 Lesson 1 - 2nd Quarter
Math 8 Lesson 1 - 2nd QuarterMath 8 Lesson 1 - 2nd Quarter
Math 8 Lesson 1 - 2nd Quarter
 
Math 8 Lesson 3 - 1st Quarter
Math 8 Lesson 3 - 1st QuarterMath 8 Lesson 3 - 1st Quarter
Math 8 Lesson 3 - 1st Quarter
 
Math 8 Lesson 2 - 1st Quarter
Math 8 Lesson 2 - 1st QuarterMath 8 Lesson 2 - 1st Quarter
Math 8 Lesson 2 - 1st Quarter
 
Math 8 Lesson 1 - 1st Quarter
Math 8 Lesson 1 - 1st QuarterMath 8 Lesson 1 - 1st Quarter
Math 8 Lesson 1 - 1st Quarter
 
General Math Lesson 1
General Math Lesson 1General Math Lesson 1
General Math Lesson 1
 
Empowerment Technology Lesson 5
Empowerment Technology Lesson 5Empowerment Technology Lesson 5
Empowerment Technology Lesson 5
 
Empowerment Technology Lesson 4
Empowerment Technology Lesson 4Empowerment Technology Lesson 4
Empowerment Technology Lesson 4
 
Empowerment Technology Lesson 3
Empowerment Technology Lesson 3Empowerment Technology Lesson 3
Empowerment Technology Lesson 3
 

Recently uploaded

The_Five_Books_Overview_Presentation_2024
The_Five_Books_Overview_Presentation_2024The_Five_Books_Overview_Presentation_2024
The_Five_Books_Overview_Presentation_2024
koheioishi1
 
TokyoTechGraduateExaminationPresentation
TokyoTechGraduateExaminationPresentationTokyoTechGraduateExaminationPresentation
TokyoTechGraduateExaminationPresentation
YukiTerazawa
 

Recently uploaded (8)

The_Five_Books_Overview_Presentation_2024
The_Five_Books_Overview_Presentation_2024The_Five_Books_Overview_Presentation_2024
The_Five_Books_Overview_Presentation_2024
 
生成AIの回答内容の修正を課題としたレポートについて:お茶の水女子大学「授業・研究における生成系AIの活用事例」での講演資料
生成AIの回答内容の修正を課題としたレポートについて:お茶の水女子大学「授業・研究における生成系AIの活用事例」での講演資料生成AIの回答内容の修正を課題としたレポートについて:お茶の水女子大学「授業・研究における生成系AIの活用事例」での講演資料
生成AIの回答内容の修正を課題としたレポートについて:お茶の水女子大学「授業・研究における生成系AIの活用事例」での講演資料
 
ゲーム理論 BASIC 演習106 -価格の交渉ゲーム-#ゲーム理論 #gametheory #数学
ゲーム理論 BASIC 演習106 -価格の交渉ゲーム-#ゲーム理論 #gametheory #数学ゲーム理論 BASIC 演習106 -価格の交渉ゲーム-#ゲーム理論 #gametheory #数学
ゲーム理論 BASIC 演習106 -価格の交渉ゲーム-#ゲーム理論 #gametheory #数学
 
次世代機の製品コンセプトを描く ~未来の機械を創造してみよう~
次世代機の製品コンセプトを描く ~未来の機械を創造してみよう~次世代機の製品コンセプトを描く ~未来の機械を創造してみよう~
次世代機の製品コンセプトを描く ~未来の機械を創造してみよう~
 
TokyoTechGraduateExaminationPresentation
TokyoTechGraduateExaminationPresentationTokyoTechGraduateExaminationPresentation
TokyoTechGraduateExaminationPresentation
 
東京工業大学 環境・社会理工学院 建築学系 大学院入学入試・進学説明会2024_v2
東京工業大学 環境・社会理工学院 建築学系 大学院入学入試・進学説明会2024_v2東京工業大学 環境・社会理工学院 建築学系 大学院入学入試・進学説明会2024_v2
東京工業大学 環境・社会理工学院 建築学系 大学院入学入試・進学説明会2024_v2
 
2024年度 東京工業大学 工学院 機械系 大学院 修士課程 入試 説明会 資料
2024年度 東京工業大学 工学院 機械系 大学院 修士課程 入試 説明会 資料2024年度 東京工業大学 工学院 機械系 大学院 修士課程 入試 説明会 資料
2024年度 東京工業大学 工学院 機械系 大学院 修士課程 入試 説明会 資料
 
世界を変えるクレーンを生み出そう! 高知エンジニアリングキャンプ2024プログラム
世界を変えるクレーンを生み出そう! 高知エンジニアリングキャンプ2024プログラム世界を変えるクレーンを生み出そう! 高知エンジニアリングキャンプ2024プログラム
世界を変えるクレーンを生み出そう! 高知エンジニアリングキャンプ2024プログラム
 

Basic Calculus Lesson 3

  • 1.
  • 2. Limit of an Exponential Function Let a and b be real numbers, where b > 0 and b ≠ 1. Then, 𝐥𝐢𝐦 𝒙→𝒂 𝒃 𝒙 = 𝒃 𝒂 .
  • 3. Properties There are four basic properties in limits, which are used as formulas in evaluating the limits of exponential functions. 1.Power Rule 2.Constant Base Power Rule 3.Constant Exponent Power Rule 4.Radical Power Rule
  • 4. 1. Power Rule 𝒍𝒊𝒎 𝒙→𝒂 𝒇 𝒙 𝒈 𝒙 = 𝒍𝒊𝒎 𝒙→𝒂 𝒇 𝒙 𝒍𝒊𝒎 𝒙→𝒂 𝒈 𝒙 It is a property of power rule, used to find the limit of an exponential function whose base and exponent are in a function form.
  • 5. 1. Power Rule 𝒍𝒊𝒎 𝒙→𝒂 𝒇 𝒙 𝒈 𝒙 = 𝒍𝒊𝒎 𝒙→𝒂 𝒇 𝒙 𝒍𝒊𝒎 𝒙→𝒂 𝒈 𝒙 Example: Evaluate 𝒇 𝒙 = 𝒙 𝟐 − 𝟒, 𝒈 𝒙 = 𝟐𝒙 ; 𝐥𝐢𝐦 𝒙→𝟑 𝒇 𝒙 𝒈 𝒙 Solution: 𝐥𝐢𝐦 𝒙→3 𝒇 𝒙 𝒈 𝒙 = 𝐥𝐢𝐦 𝒙→3 𝒇 𝒙 𝐥𝐢𝐦 𝒙→𝟑 𝒈 𝒙 = 𝐥𝐢𝐦 𝒙→3 𝒇 𝒙2 − 4 𝐥𝐢𝐦 𝒙→3 𝒈 2𝒙 = 𝟑 𝟐 − 𝟒 𝟐 𝟑 = 𝟗 − 𝟒 𝟔 = 𝟓 𝟔 = 𝟏𝟓, 𝟔𝟐𝟓
  • 6. 2. Constant Base Power Rule 𝒍𝒊𝒎 𝒙→𝒂 𝒃 𝒇 𝒙 = 𝒍𝒊𝒎 𝒙→𝒂 𝒃 𝒍𝒊𝒎 𝒙→𝒂 𝒇 𝒙 The limit of an exponential function is equal to the limit of the exponent with same base. It is called the limit rule of an exponential function.
  • 7. 2. Constant Base Power Rule 𝒍𝒊𝒎 𝒙→𝒂 𝒃 𝒇 𝒙 = 𝒍𝒊𝒎 𝒙→𝒂 𝒃 𝒍𝒊𝒎 𝒙→𝒂 𝒇 𝒙 Example: Solution: Evaluate 𝑏 = 12, 𝑓 𝑥 = 𝑥 + 3; 𝐥𝐢𝐦 𝒙→𝟏 𝒃 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→𝟏 𝒃 )𝒇(𝒙 = 𝒍𝒊𝒎 𝒙→𝟏 𝟏𝟐 𝒙+𝟑 = 𝒍𝒊𝒎 𝒙→𝟏 𝟏𝟐 𝒍𝒊𝒎 𝒙→𝟏 𝒙+𝟑 = 𝟏𝟐 𝒙+𝟑 = 𝟏𝟐 𝟏+𝟑 = 𝟏𝟐 𝟒 = 𝟐𝟎, 𝟕𝟑𝟔
  • 8. 3. Constant Exponent Power Rule 𝒍𝒊𝒎 𝒙→𝒂 𝒇 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→𝒂 𝒇 𝒙 𝒏 Example: Solution: Evaluate 𝑓 𝑥 = 16𝑥2 − 64, 𝑛 = 2; 𝐥𝐢𝐦 𝒙→𝟏 𝒇 𝒙 𝒏 𝒍𝒊𝒎 𝒙→𝟏 𝒇 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→𝟏 𝒇 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→𝟏 𝟏𝟔𝒙 𝟐 − 𝟔𝟒 𝟐 = 𝟏𝟔 𝟏 𝟐 − 𝟔𝟒 𝟐 = 𝟏𝟔 − 𝟔𝟒 𝟐 = −𝟒𝟖 𝟐 = 𝟐, 𝟑𝟎𝟒
  • 9. 4. Radical Power Rule 𝒍𝒊𝒎 𝒙→𝒂 𝒏 )𝒇(𝒙 = 𝒏 𝒍𝒊𝒎 𝒙→𝒂 )𝒇(𝒙 Example: Solution: Evaluate 𝒇 𝒙 = 𝒙 𝟐 − 𝟔𝒙 + 𝟗, 𝒏 = 𝟐; 𝒍𝒊𝒎 𝒙→𝟔 𝒏 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→𝟔 𝒏 )𝒇(𝒙 = 𝒏 𝒍𝒊𝒎 𝒙→𝟔 )𝒇(𝒙 = 𝐥𝐢𝐦 𝒙→6 𝒙2 − 6𝒙 + 9 = 𝒙 − 3 2 = 𝒙 − 3 = 6 − 3 = 𝟑
  • 10. Let’s Practice!!! 1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟐𝟒𝒙 + 𝟑𝟔, 𝒏 = 𝟐; a. 𝒍𝒊𝒎 𝒙→−𝟑 𝒏 𝒇(𝒙) b. 𝒍𝒊𝒎 𝒙→𝟒 𝒇 𝒙 𝒏 2. Evaluate 𝒇 𝒙 = 𝒙 𝟑 − 𝟐𝟕, 𝒈 𝒙 = 𝟐𝒙 + 𝟏 a. 𝒍𝒊𝒎 𝒙→𝟐 𝒇 𝒙 𝒈 𝒙 3. Evaluate 𝑏 = 𝟑, 𝑓 𝑥 = 𝒙 − 𝟒 a. 𝐥𝐢𝐦 𝒙→𝟖 𝒃 𝒇(𝒙)
  • 11. 1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟐𝟒𝒙 + 𝟑𝟔, 𝒏 = 𝟐; a. 𝒍𝒊𝒎 𝒙→−𝟑 𝒏 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→−𝟑 𝒏 )𝒇(𝒙 = 𝒏 𝒍𝒊𝒎 𝒙→−𝟑 )𝒇(𝒙 = 𝐥𝐢𝐦 𝒙→−𝟑 𝟒𝒙2 − 𝟐𝟒𝒙 + 𝟑𝟔 = 𝟐𝒙 − 𝟔 2 = 𝟐𝒙 − 𝟔 = 𝟐 −𝟑 − 𝟔 = −𝟏𝟐 = −𝟔 − 𝟔
  • 12. 1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟐𝟒𝒙 + 𝟑𝟔, 𝒏 = 𝟐; b. 𝒍𝒊𝒎 𝒙→𝟒 𝒇 𝒙 𝒏 𝒍𝒊𝒎 𝒙→𝟒 𝒇 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→𝟒 𝒇 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→𝟒 𝟒𝒙 𝟐 − 𝟐𝟒𝒙 + 𝟑𝟔 𝟐 = 𝟒 𝟒 𝟐 − 𝟐𝟒 𝟒 + 𝟑𝟔 𝟐 = 𝟒 𝟏𝟔 − 𝟗𝟔 + 𝟑𝟔 𝟐 = 𝟒 𝟐 = 𝟏𝟔 = 𝟔𝟒 − 𝟗𝟔 + 𝟑𝟔 𝟐
  • 13. 2. Evaluate 𝒇 𝒙 = 𝒙 𝟑 − 𝟐𝟕, 𝒈 𝒙 = 𝟐𝒙 + 𝟏 a. 𝒍𝒊𝒎 𝒙→𝟐 𝒇 𝒙 𝒈 𝒙 𝐥𝐢𝐦 𝒙→𝟐 𝒇 𝒙 𝒈 𝒙 = 𝐥𝐢𝐦 𝒙→2 𝒇 𝒙 𝐥𝐢𝐦 𝒙→𝟐 𝒈 𝒙 = 𝐥𝐢𝐦 𝒙→𝟐 𝒙 𝟑 − 𝟐𝟕 𝐥𝐢𝐦 𝒙→𝟐 𝟐𝐱+𝟏 = 𝟐 𝟑 − 𝟐𝟕 𝟐 𝟐 +𝟏 = 𝟖 − 𝟐𝟕 𝟓 = −𝟏𝟗 𝟓 = −𝟐, 𝟒𝟕𝟔, 𝟎𝟗𝟗
  • 14. 3. Evaluate 𝑏 = 𝟑, 𝑓 𝑥 = 𝒙 − 𝟒 a. 𝐥𝐢𝐦 𝒙→𝟖 𝒃 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→𝟖 𝒃 )𝒇(𝒙 = 𝒍𝒊𝒎 𝒙→𝟖 𝟑 𝒙−𝟒 = 𝒍𝒊𝒎 𝒙→𝟖 𝟑 𝒍𝒊𝒎 𝒙→𝟖 𝒙−𝟒 = 𝟑 𝒙−𝟒 = 𝟑 𝟖−𝟒 = 𝟑 𝟒 = 𝟖𝟏
  • 16. 1. Evaluate 𝒇 𝒙 = 𝒙 𝟐 + 𝟏𝟔𝒙 + 𝟖, 𝒏 = 𝟑; a. 𝒍𝒊𝒎 𝒙→𝟒 𝒏 𝒇(𝒙) b. 𝒍𝒊𝒎 𝒙→−𝟐 𝒇 𝒙 𝒏 2. Evaluate 𝒇 𝒙 = 𝒙 𝟐 − 𝟔𝟒, 𝒈 𝒙 = 𝒙 − 𝟓 a. 𝒍𝒊𝒎 𝒙→𝟗 𝒇 𝒙 𝒈 𝒙 b. 𝒍𝒊𝒎 𝒙→𝟗 𝒈 𝒙 𝒇 𝒙 3. Evaluate 𝑏 = 𝟏𝟓, 𝑓 𝑥 = 𝒙 𝟐 + 𝟐𝒙 + 𝟏 a. 𝐥𝐢𝐦 𝒙→𝟐 𝒃 𝒇(𝒙) b. 𝐥𝐢𝐦 𝒙→−𝟑 𝒃 𝒇(𝒙)
  • 18. 1. Evaluate 𝒇 𝒙 = 𝒙 𝟐 + 𝟏𝟔𝒙 + 𝟖, 𝒏 = 𝟑; a. 𝒍𝒊𝒎 𝒙→𝟒 𝒏 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→𝟒 𝒏 )𝒇(𝒙 = 𝒏 𝒍𝒊𝒎 𝒙→𝟒 )𝒇(𝒙 = 𝟑 𝒍𝒊𝒎 𝒙→𝟒 𝒙 𝟐 + 𝟏𝟔𝒙 + 𝟖 = 3 𝟒 𝟐 + 𝟏𝟔 𝟒 + 𝟖 = 3 𝟏𝟔 + 𝟔𝟒 + 𝟖 = 𝟒. 𝟒𝟓 = 3 𝟖𝟖
  • 19. 1. Evaluate 𝒇 𝒙 = 𝒙 𝟐 + 𝟏𝟔𝒙 + 𝟖, 𝒏 = 𝟑; b. 𝒍𝒊𝒎 𝒙→−𝟐 𝒇 𝒙 𝒏 𝒍𝒊𝒎 𝒙→−𝟐 𝒇 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→−𝟐 𝒇 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→−𝟐 𝒙 𝟐 + 𝟏𝟔𝒙 + 𝟖 𝟑 = −𝟐 𝟐 + 𝟏𝟔 −𝟐 + 𝟖 𝟑 = 𝟏𝟔 − 𝟑𝟐 + 𝟖 𝟑 = −𝟖 𝟑 = −𝟓𝟏𝟐
  • 20. 2. Evaluate 𝒇 𝒙 = 𝒙 𝟐 − 𝟔𝟒, 𝒈 𝒙 = 𝒙 − 𝟓 a. 𝒍𝒊𝒎 𝒙→𝟗 𝒇 𝒙 𝒈 𝒙 𝐥𝐢𝐦 𝒙→𝟗 𝒇 𝒙 𝒈 𝒙 = 𝐥𝐢𝐦 𝒙→9 𝒇 𝒙 𝐥𝐢𝐦 𝒙→𝟗 𝒈 𝒙 = 𝐥𝐢𝐦 𝒙→𝟗 𝒙 𝟐 − 𝟔𝟒 𝐥𝐢𝐦 𝒙→𝟗 𝐱−𝟓 = 𝟗 𝟐 − 𝟔𝟒 𝟗−𝟓 = 𝟖𝟏 − 𝟔𝟒 𝟒 = 𝟏𝟕 𝟒 = 𝟖𝟑, 𝟓𝟐𝟏
  • 21. 2. Evaluate 𝒇 𝒙 = 𝒙 𝟐 − 𝟔𝟒, 𝒈 𝒙 = 𝒙 − 𝟓 b. 𝒍𝒊𝒎 𝒙→𝟗 𝒈 𝒙 𝒇 𝒙 𝐥𝐢𝐦 𝒙→𝟗 𝒈 𝒙 𝒇 𝒙 = 𝐥𝐢𝐦 𝒙→9 𝒈 𝒙 𝐥𝐢𝐦 𝒙→𝟗 𝒇 𝒙 = 𝐥𝐢𝐦 𝒙→𝟗 𝒙 − 𝟓 𝐥𝐢𝐦 𝒙→𝟗 𝐱 𝟐−𝟔𝟒 = (𝟗 − 𝟓) 𝟗 𝟐−𝟔𝟒 = (𝟒) 𝟖𝟏−𝟔𝟒 = 𝟒 𝟏𝟕 = 𝟏𝟕, 𝟏𝟕𝟗, 𝟖𝟔𝟗, 𝟏𝟖𝟒
  • 22. 3. Evaluate 𝑏 = 𝟏𝟓, 𝑓 𝑥 = 𝒙 𝟐 + 𝟐𝒙 + 𝟏 a. 𝐥𝐢𝐦 𝒙→𝟐 𝒃 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→𝟐 𝒃 )𝒇(𝒙 = 𝒍𝒊𝒎 𝒙→𝟐 𝟏𝟓 𝒙 𝟐+𝟐𝒙+𝟏 = 𝒍𝒊𝒎 𝒙→𝟐 𝟏𝟓 𝒍𝒊𝒎 𝒙→𝟐 𝒙 𝟐+𝟐𝒙+𝟏 = 𝟏𝟓 𝒙 𝟐+𝟐𝒙+𝟏 = 𝟏𝟓 𝟐 𝟐+𝟐 𝟐 +𝟏 = 𝟏𝟓 𝟗 = 𝟑𝟖, 𝟒𝟒𝟑, 𝟑𝟓𝟗, 𝟑𝟕𝟓
  • 23. 3. Evaluate 𝑏 = 𝟏𝟓, 𝑓 𝑥 = 𝒙 𝟐 + 𝟐𝒙 + 𝟏 b. 𝐥𝐢𝐦 𝒙→−𝟑 𝒃 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→−𝟑 𝒃 )𝒇(𝒙 = 𝒍𝒊𝒎 𝒙→−𝟑 𝟏𝟓 𝒙 𝟐+𝟐𝒙+𝟏 = 𝒍𝒊𝒎 𝒙→−𝟑 𝟏𝟓 𝒍𝒊𝒎 𝒙→−𝟑 𝒙 𝟐+𝟐𝒙+𝟏 = 𝟏𝟓 𝒙 𝟐+𝟐𝒙+𝟏 = 𝟏𝟓 −𝟑 𝟐+𝟐 −𝟑 +𝟏 = 𝟏𝟓 𝟒 = 𝟓𝟎, 𝟔𝟐𝟓
  • 25. Evaluate 𝒇 𝒙 = 𝟏𝟔𝒙 𝟐 − 𝟖𝒙 + 𝟏, 𝒈 𝒙 = 𝟔𝟒𝒙 𝟐 + 𝟒𝟖𝒙 + 𝟗, 𝒏 = 𝟐; a. 𝒍𝒊𝒎 𝒙→𝟓 𝒏 𝒇(𝒙) b. 𝒍𝒊𝒎 𝒙→−𝟓 𝒇 𝒙 𝒏 c. 𝒍𝒊𝒎 𝒙→𝟖 𝒏 𝒈(𝒙) d. 𝒍𝒊𝒎 𝒙→−𝟖 𝒈 𝒙 𝒏
  • 26. Evaluate 𝒇 𝒙 = 𝟗𝒛 𝟐 − 𝟏𝟎𝟎, 𝒈 𝒙 = 𝒛 𝟐 − 𝟐𝟓 a. 𝒍𝒊𝒎 𝒛→−𝟑 𝒇 𝒙 𝒈 𝒙 b. 𝒍𝒊𝒎 𝒛→𝟑 𝒈 𝒙 𝒇 𝒙 Evaluate 𝒃 = 𝟑𝟔, 𝒇 𝒙 = 𝒙 𝟑 − 𝟐𝟕 a. 𝐥𝐢𝐦 𝒙→𝟑 𝒃 𝒇(𝒙) b. 𝐥𝐢𝐦 𝒙→𝟐 𝒃 𝒇(𝒙)
  • 28. 1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗, 𝒈 𝒙 = 𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒, 𝒏 = 𝟑; a. 𝒍𝒊𝒎 𝒙→𝟑 𝒏 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→𝟑 𝒏 )𝒇(𝒙 = 𝒏 𝒍𝒊𝒎 𝒙→𝟑 )𝒇(𝒙 = 𝟑 𝒍𝒊𝒎 𝒙→𝟑 𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗 = 3 𝟒 𝟑 𝟐 − 𝟔 𝟑 + 𝟗 = 3 𝟑𝟔 − 𝟏𝟖 + 𝟗 = 𝟑= 3 𝟐𝟕
  • 29. 1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗, 𝒈 𝒙 = 𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒, 𝒏 = 𝟑; b. 𝒍𝒊𝒎 𝒙→−𝟑 𝒇 𝒙 𝒏 𝒍𝒊𝒎 𝒙→−𝟑 𝒇 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→−𝟑 𝒇 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→−𝟑 𝟒𝒙 𝟐 − 𝟔𝒙 + 𝟗 𝟑 = 𝟒 −𝟑 𝟐 − 𝟔 −𝟑 + 𝟗 𝟑 = 𝟑𝟔 + 𝟏𝟖 + 𝟗 𝟑 = 𝟔𝟑 𝟑 = 𝟐𝟓𝟎, 𝟎𝟒𝟕
  • 30. 1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗, 𝒈 𝒙 = 𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒, 𝒏 = 𝟑; c. 𝒍𝒊𝒎 𝒙→𝟐 𝒏 𝒈(𝒙) 𝒍𝒊𝒎 𝒙→𝟐 𝒏 )𝒈(𝒙 = 𝒏 𝒍𝒊𝒎 𝒙→𝟐 )𝒈(𝒙 = 𝟑 𝒍𝒊𝒎 𝒙→𝟐 𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒 = 3 𝟐 𝟑 + 𝟖 𝟐 𝟐 − 𝟏𝟔 𝟐 + 𝟒 = 3 𝟖 + 𝟑𝟐 − 𝟑𝟐 + 𝟒 = 𝟐. 𝟐𝟗= 3 𝟏𝟐
  • 31. 1. Evaluate 𝒇 𝒙 = 𝟒 𝒙 𝟐 − 𝟔𝒙 + 𝟗, 𝒈 𝒙 = 𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒, 𝒏 = 𝟑; d. 𝒍𝒊𝒎 𝒙→−𝟐 𝒈 𝒙 𝒏 𝒍𝒊𝒎 𝒙→−𝟐 𝒈 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→−𝟐 𝒈 𝒙 𝒏 = 𝒍𝒊𝒎 𝒙→−𝟐 𝒙 𝟑 + 𝟖𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟒 𝟑 = −𝟐 𝟑 + 𝟖 −𝟐 𝟐 − 𝟏𝟔 −𝟐 + 𝟒 𝟑 = −𝟖 + 𝟑𝟐 + 𝟑𝟐 + 𝟒 𝟑 = 𝟔𝟎 𝟑 = 𝟐𝟏𝟔, 𝟎𝟎𝟎
  • 32. 2. Evaluate 𝒇 𝒙 = 𝟏𝟔𝐱 𝟐 − 𝟐𝟓, 𝒈 𝒙 = 𝒙 𝟑 − 𝟏 a. 𝒍𝒊𝒎 𝒙→𝟑 𝒇 𝒙 𝒈 𝒙 𝐥𝐢𝐦 𝒙→𝟑 𝒇 𝒙 𝒈 𝒙 = 𝐥𝐢𝐦 𝒙→3 𝒇 𝒙 𝐥𝐢𝐦 𝒙→𝟑 𝒈 𝒙 = 𝐥𝐢𝐦 𝒙→𝟑 𝟏𝟔𝒙 𝟐 − 𝟐𝟓 𝐥𝐢𝐦 𝒙→𝟑 𝐱 𝟑−𝟏 = 𝟏𝟔 𝟑 𝟐 − 𝟐𝟓 𝟑 𝟑−𝟏 = 𝟏𝟒𝟒 − 𝟐𝟓 𝟐𝟔 = 𝟏𝟏𝟗 𝟐𝟔 = 𝟗. 𝟐𝟏 × 𝟏𝟎 𝟓𝟑
  • 33. 2. Evaluate 𝒇 𝒙 = 𝟏𝟔𝐱 𝟐 − 𝟐𝟓, 𝒈 𝒙 = 𝒙 𝟑 − 𝟏 b. 𝒍𝒊𝒎 𝒙→𝟑 𝒈 𝒙 𝒇 𝒙 𝐥𝐢𝐦 𝒙→𝟑 𝒈 𝒙 𝒇 𝒙 = 𝐥𝐢𝐦 𝒙→3 𝒈 𝒙 𝐥𝐢𝐦 𝒙→𝟑 𝒇 𝒙 = 𝐥𝐢𝐦 𝒙→𝟑 𝒙 𝟑 − 𝟏 𝐥𝐢𝐦 𝒙→𝟑 𝟏𝟔𝐱 𝟐−𝟐𝟓 = ( 𝟑 𝟑 − 𝟏) 𝟏𝟔(𝟑) 𝟐−𝟐𝟓 = (𝟐𝟔) 𝟏𝟒𝟒−𝟐𝟓 = 𝟐𝟔 𝟏𝟏𝟗 = 𝟐. 𝟒𝟏 × 𝟏𝟎 𝟏𝟔𝟖
  • 34. 3. Evaluate 𝑏 = 𝟐𝟒, 𝑓 𝑥 = 𝒙 𝟑 − 𝟖 a. 𝐥𝐢𝐦 𝒙→𝟑 𝒃 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→𝟑 𝒃 )𝒇(𝒙 = 𝒍𝒊𝒎 𝒙→𝟑 𝟐𝟒 𝒙 𝟑−𝟖 = 𝒍𝒊𝒎 𝒙→𝟑 𝟐𝟒 𝒍𝒊𝒎 𝒙→𝟑 𝒙 𝟑−𝟖 = 𝟐𝟒 𝒙 𝟑−𝟖 = 𝟐𝟒 𝟑 𝟑−𝟖 = 𝟐𝟒 𝟏𝟗 = 𝟏. 𝟔𝟕 × 𝟏𝟎 𝟐𝟔
  • 35. 3. Evaluate 𝑏 = 𝟐𝟒, 𝑓 𝑥 = 𝒙 𝟑 − 𝟖 b. 𝐥𝐢𝐦 𝒙→𝟐 𝒃 𝒇(𝒙) 𝒍𝒊𝒎 𝒙→𝟐 𝒃 )𝒇(𝒙 = 𝒍𝒊𝒎 𝒙→𝟐 𝟐𝟒 𝒙 𝟑−𝟖 = 𝒍𝒊𝒎 𝒙→𝟐 𝟐𝟒 𝒍𝒊𝒎 𝒙→𝟐 𝒙 𝟑−𝟖 = 𝟐𝟒 𝒙 𝟑−𝟖 = 𝟐𝟒 𝟐 𝟑−𝟖 = 𝟐𝟒 𝟎 = 𝟏
  • 36. Limit of Logarithmic Function Let a and b be real numbers, where a > 0, b > 0 and b ≠ 1. Then, 𝒍𝒊𝒎 𝒙→𝒂 ( 𝒍𝒐𝒈 𝒃 𝒙) = 𝒍𝒐𝒈 𝒃 𝒂
  • 37. Properties There are three basic properties in limits, which are used as formulas in evaluating the limits of logarithmic functions. 1.Product Rule 2.Quotient Rule 3.Power Rule
  • 38. 1. Product Rule Example: Solution: lim 𝑥→𝑎 (log 𝑏 𝐴𝐵) = lim 𝑥→𝑎 log 𝑏 𝐴 + log 𝑏 𝐵 Given 𝑨 = 𝒙 𝟐 + 𝟐𝒙 + 𝟏, 𝑩 = 𝒙 − 𝟓, 𝒃 = 𝟓 𝒂𝒏𝒅 𝒙 = 𝟑, find 𝒍𝒊𝒎 𝒙→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) 𝒍𝒊𝒎 𝒙→𝒂 𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦 𝒙→𝟑 𝐥𝐨𝐠 𝟓(𝒙 𝟐 +𝟐𝒙 + 𝟏) + 𝐥𝐨𝐠 𝟓 𝒙 − 𝟓) = 𝐥𝐨𝐠 𝟓 𝟑 𝟐 + 𝟐 𝟑 + 𝟏 + 𝟑 − 𝟓 = 𝐥𝐨𝐠 𝟓 𝟗 + 𝟔 + 𝟏 − 𝟐 = 𝐥𝐨𝐠 𝟓 𝟏𝟒 = 𝟏. 𝟔𝟒
  • 39. 2. Quotient Rule Example: Solution: lim 𝑥→𝑎 log 𝑏( 𝐴 𝐵 ) = lim 𝑥→𝑎 log 𝑏 𝐴 − log 𝑏 𝐵 Given 𝑨 = 𝒙 𝟐 + 𝟐𝒙 + 𝟏, 𝑩 = 𝒙 − 𝟓, 𝒃 = 𝟓 𝒂𝒏𝒅 𝒙 = 𝟑, find 𝒍𝒊𝒎 𝒙→𝒂 (𝒍𝒐𝒈 𝒃 𝑨 𝑩 ) 𝒍𝒊𝒎 𝒙→𝒂 𝐥𝐨𝐠 𝒃 𝑨 𝑩 = 𝐥𝐢𝐦 𝒙→𝟑 𝐥𝐨𝐠 𝟓(𝒙 𝟐 +𝟐𝒙 + 𝟏) − 𝐥𝐨𝐠 𝟓 𝒙 − 𝟓) = 𝐥𝐨𝐠 𝟓 𝟑 𝟐 + 𝟐 𝟑 + 𝟏 − 𝟑 − 𝟓 = 𝐥𝐨𝐠 𝟓 𝟗 + 𝟔 + 𝟏 + 𝟐 = 𝐥𝐨𝐠 𝟓 𝟏𝟖 = 𝟏. 𝟕𝟗𝟔
  • 40. 3. Power Rule Example: Solution: 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏 = 𝒍𝒊𝒎 𝒙→𝒂 𝒏 𝒍𝒐𝒈 𝒃 𝑨 Given 𝑨 = 𝒙 − 𝟓, 𝒏 = 𝟑, 𝒃 = 𝟐 𝒂𝒏𝒅 𝒙 = 𝟖, find 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏 𝒍𝒊𝒎 𝒙→𝟖 𝒍𝒐𝒈 𝟐 𝒙 − 𝟓 𝟑 = 𝒍𝒊𝒎 𝒙→𝟖 𝟑 𝒍𝒐𝒈 𝟐 𝒙 − 𝟓 = 𝟑 𝒍𝒐𝒈 𝟐 𝟖 − 𝟓 = 𝟑 𝒍𝒐𝒈 𝟐 𝟑 = 𝟑 𝟏. 𝟓𝟖𝟓 = 𝟒. 𝟕𝟓𝟓
  • 41. Let’s Practice!!! 1. Given 𝑨 = 𝒙 𝟐 + 𝟒𝒙 + 𝟒, 𝑩 = 𝒙 𝟐 − 𝟏𝟔, 𝒙 = 𝟐, 𝒃 = 𝟏𝟎, 𝒏 = 𝟒 ; Find the following: a. 𝒍𝒊𝒎 𝒙→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) b. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃( 𝑨 𝑩 ) c. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏
  • 42. Solution: 𝒍𝒊𝒎 𝒙→𝒂 𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦 𝒙→𝟐 𝐥𝐨𝐠 𝟏𝟎(𝒙 𝟐 + 𝟒𝒙 + 𝟒) + 𝐥𝐨𝐠 𝟏𝟎(𝒙 𝟐 − 𝟏𝟔) = 𝐥𝐨𝐠 𝟏𝟎 𝟐 𝟐 + 𝟒 𝟐 + 𝟒 + 𝟐 𝟐 − 𝟏𝟔 = 𝐥𝐨𝐠 𝟏𝟎 𝟒 + 𝟖 + 𝟒 + 𝟒 − 𝟏𝟔 = 𝐥𝐨𝐠 𝟏𝟎 𝟒 = 𝟎. 𝟔𝟎𝟐 1. Given 𝑨 = 𝒙 𝟐 + 𝟒𝒙 + 𝟒, 𝑩 = 𝒙 𝟐 − 𝟏𝟔, 𝒙 = 𝟐, 𝒃 = 𝟏𝟎, 𝒏 = 𝟒 ;
  • 43. Solution: 𝒍𝒊𝒎 𝒙→𝒂 𝐥𝐨𝐠 𝒃 𝑨 𝑩 = 𝐥𝐢𝐦 𝒙→𝟐 𝐥𝐨𝐠 𝟏𝟎 𝒙 𝟐 + 𝟒𝒙 + 𝟒 − 𝐥𝐨𝐠 𝟏𝟎(𝒙 𝟐 − 𝟏𝟔) 1. Given 𝑨 = 𝒙 𝟐 + 𝟒𝒙 + 𝟒, 𝑩 = 𝒙 𝟐 − 𝟏𝟔, 𝒙 = 𝟐, 𝒃 = 𝟏𝟎, 𝒏 = 𝟒 ; = 𝐥𝐨𝐠 𝟏𝟎 𝟐 𝟐 + 𝟒 𝟐 + 𝟒 − 𝟐 𝟐 − 𝟏𝟔 = 𝐥𝐨𝐠 𝟏𝟎 𝟒 + 𝟖 + 𝟒 − 𝟒 + 𝟏𝟔 = 𝐥𝐨𝐠 𝟏𝟎 𝟐𝟖 = 𝟏. 𝟒𝟒𝟕
  • 44. Solution: 𝒍𝒊𝒎 𝒙→𝟐 𝒍𝒐𝒈 𝟏𝟎 𝒙 𝟐 + 𝟒𝒙 + 𝟒 𝟒 = 𝒍𝒊𝒎 𝒙→𝟐 𝟒 𝒍𝒐𝒈 𝟏𝟎 𝒙 𝟐 + 𝟒𝒙 + 𝟒 = 𝟒 𝒍𝒐𝒈 𝟏𝟎 𝟐 𝟐 + 𝟒 𝟐 + 𝟒 = 𝟒 𝒍𝒐𝒈 𝟏𝟎 𝟏𝟔 = 𝟒 𝟏. 𝟐𝟎𝟒 = 𝟒. 𝟖𝟏𝟔 1. Given 𝑨 = 𝒙 𝟐 + 𝟒𝒙 + 𝟒, 𝑩 = 𝒙 𝟐 − 𝟏𝟔, 𝒙 = 𝟐, 𝒃 = 𝟏𝟎, 𝒏 = 𝟒 ;
  • 46. 1. Given 𝑨 = 𝟗𝒙 𝟐 + 𝟑𝟎𝒙 + 𝟐𝟓, 𝑩 = 𝟒𝒙 𝟐 − 𝟏𝟔, 𝒙 = 𝟓, 𝒃 = 𝟑𝟓, 𝒏 = 𝟏𝟓 ; 2. Given 𝑨 = 𝒙 𝟐 − 𝟏𝟔𝒙 + 𝟔𝟒, 𝑩 = 𝒙 𝟐 − 𝟏, 𝒙 = 𝟑, 𝒃 = 𝟐𝟓, 𝒏 = 𝟐𝟓 Find the following: a. 𝒍𝒊𝒎 𝒙→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) b. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃( 𝑨 𝑩 ) c. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏
  • 47. 2. Given 𝑨 = 𝒙 𝟐 + 𝟐𝟎𝒙 − 𝟏𝟎𝟎, 𝑩 = 𝒙 𝟐 − 𝟑𝟔, 𝒙 = 𝟏𝟐, 𝒃 = 𝟑𝟔, 𝒏 = 𝟐𝟓 ; Find the following: a. 𝒍𝒊𝒎 𝒙→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) b. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃( 𝑨 𝑩 ) c. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏
  • 49. Solution: 𝒍𝒊𝒎 𝒙→𝒂 𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦 𝒙→𝟐 𝐥𝐨𝐠 𝟏𝟓(𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔) + 𝐥𝐨𝐠 𝟏𝟓(𝒙 𝟐 − 𝟔𝟒) = 𝐥𝐨𝐠 𝟏𝟓 𝟐𝟓 𝟐 𝟐 + 𝟒𝟎 𝟐 + 𝟏𝟔 + 𝟐 𝟐 − 𝟔𝟒 = 𝐥𝐨𝐠 𝟏𝟓 𝟏𝟎𝟎 + 𝟖𝟎 + 𝟏𝟔 + 𝟒 − 𝟔𝟒 = 𝐥𝐨𝐠 𝟏𝟓 𝟏𝟑𝟔 = 𝟏. 𝟖𝟏𝟒 1. Given 𝑨 = 𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔, 𝑩 = 𝒙 𝟐 − 𝟔𝟒, 𝒙 = 𝟐, 𝒃 = 𝟏𝟓, 𝒏 = 𝟓 ;
  • 50. Solution: 𝒍𝒊𝒎 𝒙→𝒂 𝐥𝐨𝐠 𝒃 𝑨 𝑩 = 𝐥𝐢𝐦 𝒙→𝟐 𝐥𝐨𝐠 𝟏𝟓 𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔 − 𝐥𝐨𝐠 𝟏𝟓(𝒙 𝟐 − 𝟔𝟒) 1. Given 𝑨 = 𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔, 𝑩 = 𝒙 𝟐 − 𝟔𝟒, 𝒙 = 𝟐, 𝒃 = 𝟏𝟓, 𝒏 = 𝟓 ; = 𝐥𝐨𝐠 𝟏𝟓 𝟐𝟓 𝟐 𝟐 + 𝟒𝟎 𝟐 + 𝟏𝟔 − 𝟐 𝟐 − 𝟔𝟒 = 𝐥𝐨𝐠 𝟏𝟓 𝟏𝟎𝟎 + 𝟖𝟎 + 𝟏𝟔 − 𝟒 + 𝟔𝟒 = 𝐥𝐨𝐠 𝟏𝟓 𝟐𝟓𝟔 = 𝟐. 𝟎𝟒𝟖
  • 51. Solution: 𝒍𝒊𝒎 𝒙→𝟐 𝒍𝒐𝒈 𝟏𝟓 𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔 𝟓 = 𝒍𝒊𝒎 𝒙→𝟐 𝟓 𝒍𝒐𝒈 𝟏𝟓 𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔 = 𝟓 𝒍𝒐𝒈 𝟏𝟓 𝟐𝟓 𝟐 𝟐 + 𝟒𝟎 𝟐 + 𝟏𝟔 = 𝟓 𝒍𝒐𝒈 𝟏𝟓 𝟏𝟗𝟔 = 𝟓 𝟏. 𝟗𝟒𝟗 = 𝟗. 𝟕𝟒𝟓 1. Given 𝑨 = 𝟐𝟓𝒙 𝟐 + 𝟒𝟎𝒙 + 𝟏𝟔, 𝑩 = 𝒙 𝟐 − 𝟔𝟒, 𝒙 = 𝟐, 𝒃 = 𝟏𝟓, 𝒏 = 𝟓 ;
  • 52. Solution: 𝒍𝒊𝒎 𝒙→𝒂 𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦 𝒙→𝟏𝟐 𝐥𝐨𝐠 𝟑𝟔(𝒙 𝟐 + 𝟐𝟎𝒙 − 𝟏𝟎𝟎) + 𝐥𝐨𝐠 𝟑𝟔(𝒙 𝟐 − 𝟑𝟔) = 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟐 𝟐 + 𝟐𝟎 𝟏𝟐 − 𝟏𝟎𝟎 + 𝟏𝟐 𝟐 − 𝟑𝟔 = 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟒𝟒 + 𝟐𝟒𝟎 − 𝟏𝟎𝟎 + 𝟏𝟒𝟒 − 𝟑𝟔 = 𝐥𝐨𝐠 𝟑𝟔 𝟑𝟗𝟐 = 𝟏. 𝟔𝟔𝟔 2. Given 𝑨 = 𝒙 𝟐 + 𝟐𝟎𝒙 − 𝟏𝟎𝟎, 𝑩 = 𝒙 𝟐 − 𝟑𝟔, 𝒙 = 𝟏𝟐, 𝒃 = 𝟑𝟔, 𝒏 = 𝟐𝟓 ;
  • 53. Solution: 𝒍𝒊𝒎 𝒙→𝒂 𝐥𝐨𝐠 𝒃 𝑨 𝑩 = 𝐥𝐢𝐦 𝒙→𝟏𝟐 𝐥𝐨𝐠 𝟑𝟔 𝒙 𝟐 + 𝟐𝟎𝒙 − 𝟏𝟎𝟎 − 𝐥𝐨𝐠 𝟑𝟔(𝒙 𝟐 − 𝟑𝟔) 2. Given 𝑨 = 𝒙 𝟐 + 𝟐𝟎𝒙 − 𝟏𝟎𝟎, 𝑩 = 𝒙 𝟐 − 𝟑𝟔, 𝒙 = 𝟏𝟐, 𝒃 = 𝟑𝟔, 𝒏 = 𝟐𝟓 ; = 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟐 𝟐 + 𝟐𝟎 𝟏𝟐 − 𝟏𝟎𝟎 − 𝟏𝟐 𝟐 − 𝟑𝟔 = 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟒𝟒 + 𝟐𝟒𝟎 − 𝟏𝟎𝟎 − 𝟏𝟒𝟒 + 𝟑𝟔 = 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟕𝟔 = 𝟏. 𝟒𝟒𝟑
  • 54. Solution: 𝒍𝒊𝒎 𝒙→𝟏𝟐 𝒍𝒐𝒈 𝟑𝟔 𝒙 𝟐 + 𝟐𝟎𝒙 − 𝟏𝟎𝟎 𝟐𝟓 = 𝒍𝒊𝒎 𝒙→𝟏𝟐 𝟐𝟓 𝒍𝒐𝒈 𝟑𝟔 𝒙 𝟐 + 𝟐𝟎𝒙 − 𝟏𝟎𝟎 = 𝟐𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟏𝟐 𝟐 + 𝟐𝟎 𝟏𝟐 − 𝟏𝟎𝟎 = 𝟐𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟐𝟖𝟒 = 𝟐𝟓 𝟏. 𝟓𝟕𝟔 = 𝟑𝟗. 𝟒𝟎𝟗 2. Given 𝑨 = 𝒙 𝟐 + 𝟐𝟎𝒙 − 𝟏𝟎𝟎, 𝑩 = 𝒙 𝟐 − 𝟑𝟔, 𝒙 = 𝟏𝟐, 𝒃 = 𝟑𝟔, 𝒏 = 𝟐𝟓 ;
  • 56. Given 𝑨 = 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒, 𝑩 = 𝒚 𝟐 − 𝟔𝟒, 𝒚 = 𝟓, 𝒃 = 𝟐𝟓, 𝒏 = 𝟖 ; Find the following: a. 𝒍𝒊𝒎 𝒙→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) b. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃( 𝑨 𝑩 ) c. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏
  • 57. Given 𝑨 = 𝟒𝟓𝒎 𝟐 − 𝟑𝟔𝒎 − 𝟗, 𝑩 = 𝒎 𝟐 − 𝟐𝒎 + 𝟐, 𝒎 = 𝟔, 𝒃 = 𝟑𝟔, 𝒏 = 𝟓 ; Find the following: a. 𝒍𝒊𝒎 𝒙→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) b. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃( 𝑨 𝑩 ) c. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏
  • 58. Given 𝑨 = 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔, 𝑩 = 𝒚 𝟑 − 𝟏, 𝒚 = 𝟑, 𝒃 = 𝟏𝟖, 𝒏 = 𝟔 ; Find the following: a. 𝒍𝒊𝒎 𝒙→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) b. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃( 𝑨 𝑩 ) c. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏
  • 60. Solution: 𝒍𝒊𝒎 𝐲→𝒂 𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦 𝐲→𝟓 𝐥𝐨𝐠 𝟐𝟓(𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒) + 𝐥𝐨𝐠 𝟐𝟓(𝒚 𝟐 − 𝟔𝟒) = 𝐥𝐨𝐠 𝟐𝟓 𝟑𝟔 𝟓 𝟐 − 𝟗𝟔 𝟓 + 𝟔𝟒 + 𝟓 𝟐 − 𝟔𝟒 = 𝐥𝐨𝐠 𝟐𝟓 𝟗𝟎𝟎 − 𝟒𝟖𝟎 + 𝟔𝟒 + 𝟐𝟓 − 𝟔𝟒 = 𝐥𝐨𝐠 𝟐𝟓 𝟒𝟒𝟓 = 𝟏. 𝟖𝟗𝟒 1. Given 𝑨 = 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒, 𝑩 = 𝒚 𝟐 − 𝟔𝟒, 𝒚 = 𝟓, 𝒃 = 𝟐𝟓, 𝒏 = 𝟖
  • 61. Solution: = 𝟏. 𝟗𝟒𝟓 1. Given 𝑨 = 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒, 𝑩 = 𝒚 𝟐 − 𝟔𝟒, 𝒚 = 𝟓, 𝒃 = 𝟐𝟓, 𝒏 = 𝟖 𝒍𝒊𝒎 𝐲→𝒂 𝐥𝐨𝐠 𝒃 𝑨 𝑩 = 𝐥𝐢𝐦 𝐲→𝟓 𝐥𝐨𝐠 𝟐𝟓 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒 − 𝐥𝐨𝐠 𝟐𝟓(𝒚 𝟐 − 𝟔𝟒) = 𝐥𝐨𝐠 𝟐𝟓 𝟑𝟔 𝟓 𝟐 − 𝟗𝟔 𝟓 + 𝟔𝟒 − 𝟓 𝟐 − 𝟔𝟒 = 𝐥𝐨𝐠 𝟐𝟓 𝟗𝟎𝟎 − 𝟒𝟖𝟎 + 𝟔𝟒 − 𝟐𝟓 + 𝟔𝟒 = 𝐥𝐨𝐠 𝟐𝟓 𝟓𝟐𝟑
  • 62. Solution: 𝒍𝒊𝒎 𝒚→𝟓 𝒍𝒐𝒈 𝟐𝟓 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒 𝟖 = 𝒍𝒊𝒎 𝒚→𝟓 𝟖 𝒍𝒐𝒈 𝟐𝟓 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒 = 𝟖 𝒍𝒐𝒈 𝟐𝟓 𝟑𝟔 𝟓 𝟐 − 𝟗𝟔 𝟓 + +𝟔𝟒 = 𝟖 𝒍𝒐𝒈 𝟐𝟓 𝟒𝟖𝟒 = 𝟖 𝟏. 𝟗𝟐𝟏 = 𝟏𝟓. 𝟑𝟔𝟓 1. Given 𝑨 = 𝟑𝟔𝒚 𝟐 − 𝟗𝟔𝒚 + 𝟔𝟒, 𝑩 = 𝒚 𝟐 − 𝟔𝟒, 𝒚 = 𝟓, 𝒃 = 𝟐𝟓, 𝒏 = 𝟖
  • 63. Solution: 𝒍𝒊𝒎 𝐦→𝒂 𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦 𝐦→𝟔 𝐥𝐨𝐠 𝟑𝟔(𝟒𝟓𝒎 𝟐 − 𝟑𝟔𝒎 − 𝟗) + 𝐥𝐨𝐠 𝟑𝟔(𝒎 𝟐 − 𝟐𝒎 + 𝟐) = 𝐥𝐨𝐠 𝟑𝟔 𝟒𝟓 𝟔 𝟐 − 𝟑𝟔 𝟔 − 𝟗 + 𝟔 𝟐 − 𝟐 𝟔 + 𝟐 = 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟔𝟐𝟎 − 𝟐𝟏𝟔 − 𝟗 + 𝟑𝟔 − 𝟏𝟐 + 𝟐 = 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟒𝟐𝟏 = 𝟐. 𝟎𝟐𝟔 2. Given 𝑨 = 𝟒𝟓𝒎 𝟐 − 𝟑𝟔𝒎 − 𝟗, 𝑩 = 𝒎 𝟐 − 𝟐𝒎 + 𝟐, 𝒎 = 𝟔, 𝒃 = 𝟑𝟔, 𝒏 = 𝟓 ;
  • 64. Solution: = 𝟐. 𝟎𝟏𝟓 2. Given 𝑨 = 𝟒𝟓𝒎 𝟐 − 𝟑𝟔𝒎 − 𝟗, 𝑩 = 𝒎 𝟐 − 𝟐𝒎 + 𝟐, 𝒎 = 𝟔, 𝒃 = 𝟑𝟔, 𝒏 = 𝟓 ; 𝒍𝒊𝒎 𝐦→𝒂 𝐥𝐨𝐠 𝒃 𝑨 𝑩 = 𝐥𝐢𝐦 𝐦→𝟔 𝐥𝐨𝐠 𝟑𝟔 𝟒𝟓𝒎 𝟐 − 𝟑𝟔𝒎 − 𝟗 − 𝐥𝐨𝐠 𝟑𝟔(𝒎 𝟐 − 𝟐𝒎 + 𝟐) = 𝐥𝐨𝐠 𝟑𝟔 𝟒𝟓 𝟔 𝟐 − 𝟑𝟔 𝟔 − 𝟗 − 𝟔 𝟐 − 𝟐 𝟔 + 𝟐 = 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟔𝟐𝟎 − 𝟐𝟏𝟔 − 𝟗 − 𝟑𝟔 + 𝟏𝟐 − 𝟐 = 𝐥𝐨𝐠 𝟑𝟔 𝟏𝟑𝟔𝟗
  • 65. Solution: 𝒍𝒊𝒎 𝒎→𝟔 𝒍𝒐𝒈 𝟑𝟔 𝟒𝟓𝒎 𝟐 − 𝟑𝟔𝒎 − 𝟗 𝟓 = 𝒍𝒊𝒎 𝒙→𝟐 𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟒𝟓𝒎 𝟐 − 𝟑𝟔𝒎 − 𝟗 = 𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟒𝟓 𝟔 𝟐 − 𝟑𝟔 𝟔 − 𝟗 = 𝟓 𝒍𝒐𝒈 𝟑𝟔 𝟏𝟑𝟗𝟓 = 𝟓 𝟐. 𝟎𝟐𝟏 = 𝟏𝟎. 𝟏𝟎𝟑 2. Given 𝑨 = 𝟒𝟓𝒎 𝟐 − 𝟑𝟔𝒎 − 𝟗, 𝑩 = 𝒎 𝟐 − 𝟐𝒎 + 𝟐, 𝒎 = 𝟔, 𝒃 = 𝟑𝟔, 𝒏 = 𝟓 ;
  • 66. Solution: 𝒍𝒊𝒎 𝐲→𝒂 𝐥𝐨𝐠 𝒃 𝑨𝑩 = 𝐥𝐢𝐦 𝒚→𝟑 𝐥𝐨𝐠 𝟏𝟖(𝟏𝟔𝒚 𝟐 − 𝟒𝟔𝒚 + 𝟑𝟔) + 𝐥𝐨𝐠 𝟏𝟖(𝒚 𝟑 − 𝟏) = 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟔 𝟑 𝟐 − 𝟒𝟖 𝟑 + 𝟑𝟔 + 𝟑 𝟑 − 𝟏 = 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟒𝟒 − 𝟏𝟒𝟒 + 𝟑𝟔 + 𝟐𝟕 − 𝟏 = 𝐥𝐨𝐠 𝟏𝟖 𝟔𝟐 = 𝟏. 𝟒𝟐𝟖 3. Given 𝑨 = 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔, 𝑩 = 𝒚 𝟑 − 𝟏, 𝒚 = 𝟑, 𝒃 = 𝟏𝟖, 𝒏 = 𝟔 ;
  • 67. Solution: = 𝟎. 𝟕𝟗𝟕 3. Given 𝑨 = 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔, 𝑩 = 𝒚 𝟑 − 𝟏, 𝒚 = 𝟑, 𝒃 = 𝟏𝟖, 𝒏 = 𝟔 ; 𝒍𝒊𝒎 𝐲→𝒂 𝐥𝐨𝐠 𝒃 𝑨 𝑩 = 𝐥𝐢𝐦 𝒚→𝟑 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟔𝒚 𝟐 − 𝟒𝟔𝒚 + 𝟑𝟔 − 𝐥𝐨𝐠 𝟏𝟖(𝒚 𝟑 − 𝟏) = 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟔 𝟑 𝟐 − 𝟒𝟖 𝟑 + 𝟑𝟔 − 𝟑 𝟐 − 𝟏 = 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟒𝟒 − 𝟏𝟒𝟒 + 𝟑𝟔 − 𝟐𝟕 + 𝟏 = 𝐥𝐨𝐠 𝟏𝟖 𝟏𝟎
  • 68. Solution: 𝒍𝒊𝒎 𝒚→𝟑 𝒍𝒐𝒈 𝟏𝟖 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔 𝟔 = 𝒍𝒊𝒎 𝒚→𝟑 𝟔 𝒍𝒐𝒈 𝟏𝟖 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔 = 𝟔 𝒍𝒐𝒈 𝟏𝟖 𝟏𝟔 𝟑 𝟐 − 𝟒𝟖 𝟑 + 𝟑𝟔 = 𝟔 𝒍𝒐𝒈 𝟏𝟖 𝟑𝟔 = 𝟔 𝟏. 𝟐𝟒𝟎 = 𝟕. 𝟒𝟑𝟗 3. Given 𝑨 = 𝟏𝟔𝒚 𝟐 − 𝟒𝟖𝒚 + 𝟑𝟔, 𝑩 = 𝒚 𝟑 − 𝟏, 𝒚 = 𝟑, 𝒃 = 𝟏𝟖, 𝒏 = 𝟔 ;
  • 69. Pointers to Review Limits of Non – Algebraic Functions Limit of an Exponential Function Limit of Logarithmic Function
  • 70. Given 𝑨 = 𝒚 𝟐 + 𝟔𝒚 + 𝟗, 𝑩 = 𝟒𝒚 𝟐 − 𝟏, 𝒚 = 𝟖, 𝒃 = 𝟏𝟓, 𝒏 = 𝟔 ; Find the following: a. 𝒍𝒊𝒎 𝒚→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) b. 𝒍𝒊𝒎 𝒚→𝒂 𝒍𝒐𝒈 𝒃( 𝑨 𝑩 ) c. 𝒍𝒊𝒎 𝒚→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏
  • 71. Given 𝑨 = 𝟑𝒙 𝟐 + 𝟗𝒙 + 𝟗, 𝑩 = 𝒙 − 𝟓, 𝒙 = 𝟐, 𝒃 = 𝟏𝟑, 𝒏 = 𝟏𝟎 ; Find the following: a. 𝒍𝒊𝒎 𝒙→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) b. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃( 𝑨 𝑩 ) c. 𝒍𝒊𝒎 𝒙→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏
  • 72. Given 𝑨 = 𝟔𝒛 𝟐 − 𝟒𝒛 + 𝟓, 𝑩 = 𝟐𝒛 𝟐 + 𝟒𝒛 − 𝟑, 𝒛 = 𝟑, 𝒃 = 𝟖, 𝒏 = 𝟐; Find the following: a. 𝒍𝒊𝒎 𝒛→𝒂 (𝒍𝒐𝒈 𝒃 𝑨𝑩) b. 𝒍𝒊𝒎 𝒛→𝒂 𝒍𝒐𝒈 𝒃( 𝑨 𝑩 ) c. 𝒍𝒊𝒎 𝒛→𝒂 𝒍𝒐𝒈 𝒃 𝑨 𝒏