2. Radicals and Square-Equations
We need a scientific calculator for thin section.
You may use the digital calculators on your personal devices.
Make sure the calculator could displace your input so that
you may check the input before executing it.
3. Radicals and Square-Equations
We need a scientific calculator for thin section.
You may use the digital calculators on your personal devices.
Make sure the calculator could displace your input so that
you may check the input before executing it.
Square Root
4. β9 is the square of 3β may be rephrased backwards as
β3 is the square root of 9β.
Radicals and Square-Equations
We need a scientific calculator for thin section.
You may use the digital calculators on your personal devices.
Make sure the calculator could displace your input so that
you may check the input before executing it.
Square Root
5. β9 is the square of 3β may be rephrased backwards as
β3 is the square root of 9β.
Radicals and Square-Equations
Definition: If a is > 0, and a2 = x, then we say a is the square
root of x. This is written as sqrt(x) = a, or οx = a.
We need a scientific calculator for thin section.
You may use the digital calculators on your personal devices.
Make sure the calculator could displace your input so that
you may check the input before executing it.
Square Root
6. β9 is the square of 3β may be rephrased backwards as
β3 is the square root of 9β.
Example D.
a. Sqrt(16) =
c.οβ3 =
Radicals and Square-Equations
Definition: If a is > 0, and a2 = x, then we say a is the square
root of x. This is written as sqrt(x) = a, or οx = a.
b. ο1/9 =
d. ο3 =
We need a scientific calculator for thin section.
You may use the digital calculators on your personal devices.
Make sure the calculator could displace your input so that
you may check the input before executing it.
Square Root
7. β9 is the square of 3β may be rephrased backwards as
β3 is the square root of 9β.
Example D.
a. Sqrt(16) = 4
c.οβ3 =
Radicals and Square-Equations
Definition: If a is > 0, and a2 = x, then we say a is the square
root of x. This is written as sqrt(x) = a, or οx = a.
b. ο1/9 = 1/3
d. ο3 =
We need a scientific calculator for thin section.
You may use the digital calculators on your personal devices.
Make sure the calculator could displace your input so that
you may check the input before executing it.
Square Root
8. β9 is the square of 3β may be rephrased backwards as
β3 is the square root of 9β.
Example D.
a. Sqrt(16) = 4
c.οβ3 = doesnβt exist
Radicals and Square-Equations
Definition: If a is > 0, and a2 = x, then we say a is the square
root of x. This is written as sqrt(x) = a, or οx = a.
b. ο1/9 = 1/3
d. ο3 =
We need a scientific calculator for thin section.
You may use the digital calculators on your personal devices.
Make sure the calculator could displace your input so that
you may check the input before executing it.
Square Root
9. β9 is the square of 3β may be rephrased backwards as
β3 is the square root of 9β.
Example D.
a. Sqrt(16) = 4
c.οβ3 = doesnβt exist
Radicals and Square-Equations
Definition: If a is > 0, and a2 = x, then we say a is the square
root of x. This is written as sqrt(x) = a, or οx = a.
b. ο1/9 = 1/3
d. ο3 = 1.732.. (calculator)
We need a scientific calculator for thin section.
You may use the digital calculators on your personal devices.
Make sure the calculator could displace your input so that
you may check the input before executing it.
Square Root
10. β9 is the square of 3β may be rephrased backwards as
β3 is the square root of 9β.
Example D.
a. Sqrt(16) = 4
c.οβ3 = doesnβt exist
Radicals and Square-Equations
Definition: If a is > 0, and a2 = x, then we say a is the square
root of x. This is written as sqrt(x) = a, or οx = a.
b. ο1/9 = 1/3
d. ο3 = 1.732.. (calculator)
Note that the square of both +3 and β3 is 9,
but we designate sqrt(9) or ο9 to be +3.
We say ββ3β is the βnegative of the square root of 9β.
We need a scientific calculator for thin section.
You may use the digital calculators on your personal devices.
Make sure the calculator could displace your input so that
you may check the input before executing it.
Square Root
12. 0 02 = 0 ο0 = 0
1 12 = 1 ο1 = 1
2 22 = 4 ο4 = 2
3 32 = 9 ο9 = 3
4 42 = 16 ο16 = 4
5 52 = 25 ο25 = 5
6 62 = 36 ο36 = 6
7 72 = 49 ο49 = 7
8 82 = 64 ο64 = 8
9 92 = 81 ο81 = 9
10 102 = 100 ο100 = 10
11 112 = 121 ο121 = 11
Radicals and Square-Equations
Following are the square numbers and square-roots that one
needs to memorize. These numbers are special because
many mathematics exercises utilize square numbers.
13. 0 02 = 0 ο0 = 0
1 12 = 1 ο1 = 1
2 22 = 4 ο4 = 2
3 32 = 9 ο9 = 3
4 42 = 16 ο16 = 4
5 52 = 25 ο25 = 5
6 62 = 36 ο36 = 6
7 72 = 49 ο49 = 7
8 82 = 64 ο64 = 8
9 92 = 81 ο81 = 9
10 102 = 100 ο100 = 10
11 112 = 121 ο121 = 11
We may estimate the sqrt
of other small numbers using
this table.
Radicals and Square-Equations
Following are the square numbers and square-roots that one
needs to memorize. These numbers are special because
many mathematics exercises utilize square numbers.
14. 0 02 = 0 ο0 = 0
1 12 = 1 ο1 = 1
2 22 = 4 ο4 = 2
3 32 = 9 ο9 = 3
4 42 = 16 ο16 = 4
5 52 = 25 ο25 = 5
6 62 = 36 ο36 = 6
7 72 = 49 ο49 = 7
8 82 = 64 ο64 = 8
9 92 = 81 ο81 = 9
10 102 = 100 ο100 = 10
11 112 = 121 ο121 = 11
We may estimate the sqrt
of other small numbers using
this table. For example,
25 < 30 < 36
Radicals and Square-Equations
Following are the square numbers and square-roots that one
needs to memorize. These numbers are special because
many mathematics exercises utilize square numbers.
15. 0 02 = 0 ο0 = 0
1 12 = 1 ο1 = 1
2 22 = 4 ο4 = 2
3 32 = 9 ο9 = 3
4 42 = 16 ο16 = 4
5 52 = 25 ο25 = 5
6 62 = 36 ο36 = 6
7 72 = 49 ο49 = 7
8 82 = 64 ο64 = 8
9 92 = 81 ο81 = 9
10 102 = 100 ο100 = 10
11 112 = 121 ο121 = 11
We may estimate the sqrt
of other small numbers using
this table. For example,
25 < 30 < 36
hence
ο25 < ο30 <ο36
Radicals and Square-Equations
Following are the square numbers and square-roots that one
needs to memorize. These numbers are special because
many mathematics exercises utilize square numbers.
16. 0 02 = 0 ο0 = 0
1 12 = 1 ο1 = 1
2 22 = 4 ο4 = 2
3 32 = 9 ο9 = 3
4 42 = 16 ο16 = 4
5 52 = 25 ο25 = 5
6 62 = 36 ο36 = 6
7 72 = 49 ο49 = 7
8 82 = 64 ο64 = 8
9 92 = 81 ο81 = 9
10 102 = 100 ο100 = 10
11 112 = 121 ο121 = 11
We may estimate the sqrt
of other small numbers using
this table. For example,
25 < 30 < 36
hence
ο25 < ο30 <ο36
or 5 < ο30 < 6
Radicals and Square-Equations
Following are the square numbers and square-roots that one
needs to memorize. These numbers are special because
many mathematics exercises utilize square numbers.
17. 0 02 = 0 ο0 = 0
1 12 = 1 ο1 = 1
2 22 = 4 ο4 = 2
3 32 = 9 ο9 = 3
4 42 = 16 ο16 = 4
5 52 = 25 ο25 = 5
6 62 = 36 ο36 = 6
7 72 = 49 ο49 = 7
8 82 = 64 ο64 = 8
9 92 = 81 ο81 = 9
10 102 = 100 ο100 = 10
11 112 = 121 ο121 = 11
We may estimate the sqrt
of other small numbers using
this table. For example,
25 < 30 < 36
hence
ο25 < ο30 <ο36
or 5 < ο30 < 6
Since 30 is about half way
between 25 and 36,
Radicals and Square-Equations
Following are the square numbers and square-roots that one
needs to memorize. These numbers are special because
many mathematics exercises utilize square numbers.
18. 0 02 = 0 ο0 = 0
1 12 = 1 ο1 = 1
2 22 = 4 ο4 = 2
3 32 = 9 ο9 = 3
4 42 = 16 ο16 = 4
5 52 = 25 ο25 = 5
6 62 = 36 ο36 = 6
7 72 = 49 ο49 = 7
8 82 = 64 ο64 = 8
9 92 = 81 ο81 = 9
10 102 = 100 ο100 = 10
11 112 = 121 ο121 = 11
We may estimate the sqrt
of other small numbers using
this table. For example,
25 < 30 < 36
hence
ο25 < ο30 <ο36
or 5 < ο30 < 6
Since 30 is about half way
between 25 and 36,
so we estimate thatο30 ο» 5.5.
Radicals and Square-Equations
Following are the square numbers and square-roots that one
needs to memorize. These numbers are special because
many mathematics exercises utilize square numbers.
19. 0 02 = 0 ο0 = 0
1 12 = 1 ο1 = 1
2 22 = 4 ο4 = 2
3 32 = 9 ο9 = 3
4 42 = 16 ο16 = 4
5 52 = 25 ο25 = 5
6 62 = 36 ο36 = 6
7 72 = 49 ο49 = 7
8 82 = 64 ο64 = 8
9 92 = 81 ο81 = 9
10 102 = 100 ο100 = 10
11 112 = 121 ο121 = 11
We may estimate the sqrt
of other small numbers using
this table. For example,
25 < 30 < 36
hence
ο25 < ο30 <ο36
or 5 < ο30 < 6
Since 30 is about half way
between 25 and 36,
so we estimate thatο30 ο» 5.5.
In fact ο30 ο» 5.47722β¦.
Radicals and Square-Equations
Following are the square numbers and square-roots that one
needs to memorize. These numbers are special because
many mathematics exercises utilize square numbers.
20. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
21. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
(If c<0, there is no real solution.)
22. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
(If c<0, there is no real solution.)
23. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
x = Β±ο25
(If c<0, there is no real solution.)
24. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
x = Β±ο25 = Β±5
(If c<0, there is no real solution.)
25. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
x = Β±ο25 = Β±5
b. x2 = β4
(If c<0, there is no real solution.)
26. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
x = Β±ο25 = Β±5
b. x2 = β4
Solution does not exist.
(If c<0, there is no real solution.)
27. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
x = Β±ο25 = Β±5
b. x2 = β4
Solution does not exist.
c. x2 = 8
(If c<0, there is no real solution.)
28. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
x = Β±ο25 = Β±5
b. x2 = β4
Solution does not exist.
c. x2 = 8
x = Β±ο8
(If c<0, there is no real solution.)
29. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
x = Β±ο25 = Β±5
b. x2 = β4
Solution does not exist.
c. x2 = 8
x = Β±ο8 ο» Β±2.8284.. by calculator
(If c<0, there is no real solution.)
30. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
x = Β±ο25 = Β±5
b. x2 = β4
Solution does not exist.
c. x2 = 8
x = Β±ο8 ο» Β±2.8284.. by calculator
exact answer approximate answer
(If c<0, there is no real solution.)
31. Equations of the form x2 = c has two answers:
x = +οc or βοc if c>0.
Radicals and Square-Equations
Example E. Solve the following equations.
a. x2 = 25
x = Β±ο25 = Β±5
b. x2 = β4
Solution does not exist.
c. x2 = 8
x = Β±ο8 ο» Β±2.8284.. by calculator
exact answer approximate answer
Square-roots numbers show up in geometry for measuring
distances because of the Pythagorean Theorem.
(If c<0, there is no real solution.)
32. Rules of Radicals
For the following discussion of square roots,
the variables x and y are assumed β₯ 0.
33. Square Rule: οx2 =οx οx = x
Rules of Radicals
For the following discussion of square roots,
the variables x and y are assumed β₯ 0.
34. Square Rule: οx2 =οx οx = x
Rules of Radicals
For the following discussion of square roots,
the variables x and y are assumed β₯ 0.
Hence ο3 Β·ο3 = 3,
ο(x + 1)2 = οx + 1 Β· ο x + 1 = x + 1
35. Square Rule: οx2 =οx οx = x
Multiplication Rule: οxΒ·y = οxΒ·οy
Rules of Radicals
For the following discussion of square roots,
the variables x and y are assumed β₯ 0.
Hence ο3 Β·ο3 = 3,
ο(x + 1)2 = οx + 1 Β· ο x + 1 = x + 1
36. Square Rule: οx2 =οx οx = x
Multiplication Rule: οxΒ·y = οxΒ·οy
Rules of Radicals
For the following discussion of square roots,
the variables x and y are assumed β₯ 0.
Hence ο3 Β·ο3 = 3,
ο(x + 1)2 = οx + 1 Β· ο x + 1 = x + 1
Hence ο12 Β·ο3 = ο36 = 6
ο12 Β·ο1/3 = ο12 Β·(1/3) = ο1/4 = 1/2
37. Square Rule: οx2 =οx οx = x
Multiplication Rule: οxΒ·y = οxΒ·οy
Rules of Radicals
For the following discussion of square roots,
the variables x and y are assumed β₯ 0.
Division Rule: οx/y = οx /οy
Hence ο3 Β·ο3 = 3,
ο(x + 1)2 = οx + 1 Β· ο x + 1 = x + 1
Hence ο12 Β·ο3 = ο36 = 6
ο12 Β·ο1/3 = ο12 Β·(1/3) = ο1/4 = 1/2
38. Square Rule: οx2 =οx οx = x
Multiplication Rule: οxΒ·y = οxΒ·οy
Rules of Radicals
For the following discussion of square roots,
the variables x and y are assumed β₯ 0.
Division Rule: οx/y = οx /οy
Hence ο3 Β·ο3 = 3,
ο(x + 1)2 = οx + 1 Β· ο x + 1 = x + 1
Hence ο12 Β·ο3 = ο36 = 6
ο12 Β·ο1/3 = ο12 Β·(1/3) = ο1/4 = 1/2
Hence ο12 /ο3 = ο12/3 = ο4 = 2
39. Square Rule: οx2 =οx οx = x
Multiplication Rule: οxΒ·y = οxΒ·οy
Rules of Radicals
For the following discussion of square roots,
the variables x and y are assumed β₯ 0.
Division Rule: οx/y = οx /οy
Hence ο3 Β·ο3 = 3,
ο(x + 1)2 = οx + 1 Β· ο x + 1 = x + 1
Hence ο12 Β·ο3 = ο36 = 6
ο12 Β·ο1/3 = ο12 Β·(1/3) = ο1/4 = 1/2
Note that οx Β± y β οx Β± οy
Hence ο12 /ο3 = ο12/3 = ο4 = 2
40. Square Rule: οx2 =οx οx = x
Multiplication Rule: οxΒ·y = οxΒ·οy
Rules of Radicals
For the following discussion of square roots,
the variables x and y are assumed β₯ 0.
Division Rule: οx/y = οx /οy
Hence ο3 Β·ο3 = 3,
ο(x + 1)2 = οx + 1 Β· ο x + 1 = x + 1
Hence ο12 Β·ο3 = ο36 = 6
ο12 Β·ο1/3 = ο12 Β·(1/3) = ο1/4 = 1/2
Note that οx Β± y β οx Β± οy
so that ο13 = ο4 + 9 β ο4 + ο9 = 5
οx2 β 4 β x β 2
Hence ο12 /ο3 = ο12/3 = ο4 = 2
where as ο(x β 2)2 = οx2 β 4x + 4 = l x β 2 l
42. Solving 2nd Degree Equations ax2 + bx + c = 0
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
43. Solving 2nd Degree Equations ax2 + bx + c = 0
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
44. Solving 2nd Degree Equations ax2 + bx + c = 0
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
45. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
46. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
47. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
I. Solve for the x2 and get the form x2 = d.
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
48. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
I. Solve for the x2 and get the form x2 = d.
II. Then x = Β±οd are the roots.
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
49. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
I. Solve for the x2 and get the form x2 = d.
II. Then x = Β±οd are the roots.
Example F. Solve 3x2 β 7 = 0
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
50. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
I. Solve for the x2 and get the form x2 = d.
II. Then x = Β±οd are the roots.
Example F. Solve 3x2 β 7 = 0
3x2 β 7 = 0 solve for x2
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
51. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
I. Solve for the x2 and get the form x2 = d.
II. Then x = Β±οd are the roots.
Example F. Solve 3x2 β 7 = 0
3x2 β 7 = 0 solve for x2
3x2 = 7
x2 = 7
3
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
52. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
I. Solve for the x2 and get the form x2 = d.
II. Then x = Β±οd are the roots.
Example F. Solve 3x2 β 7 = 0
3x2 β 7 = 0 solve for x2
3x2 = 7
x2 = take square root
x = Β±ο7/3
7
3
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
53. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
I. Solve for the x2 and get the form x2 = d
II. Then x = Β±οd are the roots.
Example F. Solve 3x2 β 7 = 0
3x2 β 7 = 0 solve for x2
3x2 = 7
x2 = take square root
x = Β±ο7/3 ο» Β±1.53
7
3
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
54. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
I. Solve for the x2 and get the form x2 = d
II. Then x = Β±οd are the roots.
Example F. Solve 3x2 β 7 = 0
3x2 β 7 = 0 solve for x2
3x2 = 7
x2 = take square root
x = Β±ο7/3 ο» Β±1.53
7
3
exact answers
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
55. Solving 2nd Degree Equations ax2 + bx + c = 0
The Square-Root Method
Use the square-root method if there is no x-term.
I. Solve for the x2 and get the form x2 = d
II. Then x = Β±οd are the roots.
Example F. Solve 3x2 β 7 = 0
3x2 β 7 = 0 solve for x2
3x2 = 7
x2 = take square root
x = Β±ο7/3 ο» Β±1.53
7
3
exact answers
approx. answers
To solve ax2 + bx + c = 0:
1st: Use the square-root method if the x-term is missing.
2nd: Try factoring it into two binomials.
3rd: Use the quadratic formula (QF).
In this course,
all approx. answers
are given with three
significant digits, i.e.
starting from the first
nonzero digit, round
off the answer to a
three digit number.
56. 2. Solve by the factoring method
Factor the equation into the form (#x + #)(#x + #) = 0 and
obtain a solution from each binomial factor.
Solving 2nd Degree Equations ax2 + bx + c = 0
57. Example G. Solve the by the factoring method.
2. Solve by the factoring method
Factor the equation into the form (#x + #)(#x + #) = 0 and
obtain a solution from each binomial factor.
Solving 2nd Degree Equations ax2 + bx + c = 0
b. x(3x β 3) = βx + 8
a. 2x2 β 8x = 0
58. Example G. Solve the by the factoring method.
2. Solve by the factoring method
Factor the equation into the form (#x + #)(#x + #) = 0 and
obtain a solution from each binomial factor.
Solving 2nd Degree Equations ax2 + bx + c = 0
b. x(3x β 3) = βx + 8
a. 2x2 β 8x = 0
2x(x β 4) = 0
59. Example G. Solve the by the factoring method.
2. Solve by the factoring method
Factor the equation into the form (#x + #)(#x + #) = 0 and
obtain a solution from each binomial factor.
Solving 2nd Degree Equations ax2 + bx + c = 0
b. x(3x β 3) = βx + 8
a. 2x2 β 8x = 0
2x(x β 4) = 0
hence x = 0
or x β 4 = 0 so x = 4
60. Example G. Solve the by the factoring method.
2. Solve by the factoring method
Factor the equation into the form (#x + #)(#x + #) = 0 and
obtain a solution from each binomial factor.
Solving 2nd Degree Equations ax2 + bx + c = 0
b. x(3x β 3) = βx + 8
3x2 β 3x + x β 8 = 0
a. 2x2 β 8x = 0
2x(x β 4) = 0
hence x = 0
or x β 4 = 0 so x = 4
set one side to be 0
61. Example G. Solve the by the factoring method.
2. Solve by the factoring method
Factor the equation into the form (#x + #)(#x + #) = 0 and
obtain a solution from each binomial factor.
Solving 2nd Degree Equations ax2 + bx + c = 0
b. x(3x β 3) = βx + 8
3x2 β 3x + x β 8 = 0
3x2 β 2x β 8 = 0
a. 2x2 β 8x = 0
2x(x β 4) = 0
hence x = 0
or x β 4 = 0 so x = 4
set one side to be 0
62. Example G. Solve the by the factoring method.
2. Solve by the factoring method
Factor the equation into the form (#x + #)(#x + #) = 0 and
obtain a solution from each binomial factor.
Solving 2nd Degree Equations ax2 + bx + c = 0
b. x(3x β 3) = βx + 8
3x2 β 3x + x β 8 = 0
3x2 β 2x β 8 = 0
(3x + 4)(x β 2) = 0
a. 2x2 β 8x = 0
2x(x β 4) = 0
hence x = 0
or x β 4 = 0 so x = 4
set one side to be 0
factor
63. Example G. Solve the by the factoring method.
2. Solve by the factoring method
Factor the equation into the form (#x + #)(#x + #) = 0 and
obtain a solution from each binomial factor.
Solving 2nd Degree Equations ax2 + bx + c = 0
b. x(3x β 3) = βx + 8
3x2 β 3x + x β 8 = 0
3x2 β 2x β 8 = 0
(3x + 4)(x β 2) = 0
x = β4/3, x = 2
a. 2x2 β 8x = 0
2x(x β 4) = 0
hence x = 0
or x β 4 = 0 so x = 4
set one side to be 0
factor and extract the solutions
64. Example G. Solve the by the factoring method.
2. Solve by the factoring method
Factor the equation into the form (#x + #)(#x + #) = 0 and
obtain a solution from each binomial factor.
Solving 2nd Degree Equations ax2 + bx + c = 0
b. x(3x β 3) = βx + 8
3x2 β 3x + x β 8 = 0
3x2 β 2x β 8 = 0
(3x + 4)(x β 2) = 0
x = β4/3, x = 2
a. 2x2 β 8x = 0
2x(x β 4) = 0
hence x = 0
or x β 4 = 0 so x = 4
set one side to be 0
factor and extract the solutions
If the equation is not easily factorable, use the formula below.
65. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
66. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are.
67. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
68. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
69. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
Example H. Solve 3x2 β 2x β 2 = 0
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
70. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
Example H. Solve 3x2 β 2x β 2 = 0
Check if it is factorable: a = 3, b = β2, c = β2
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
71. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
Example H. Solve 3x2 β 2x β 2 = 0
Check if it is factorable: a = 3, b = β2, c = β2
So b2 β 4ac = (β2)2 β 4(3)(β2) = 28.
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
72. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
Example H. Solve 3x2 β 2x β 2 = 0
Check if it is factorable: a = 3, b = β2, c = β2
So b2 β 4ac = (β2)2 β 4(3)(β2) = 28. Not factorable!
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
73. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
Example H. Solve 3x2 β 2x β 2 = 0
Check if it is factorable: a = 3, b = β2, c = β2
So b2 β 4ac = (β2)2 β 4(3)(β2) = 28. Not factorable!
Use QF, we get
x = β (β2) Β± ο 28
2(3)
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
74. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
Example H. Solve 3x2 β 2x β 2 = 0
Check if it is factorable: a = 3, b = β2, c = β2
So b2 β 4ac = (β2)2 β 4(3)(β2) = 28. Not factorable!
Use QF, we get
x = β (β2) Β± ο 28
2(3)
=
2 Β± ο 28
6
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
75. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
Example H. Solve 3x2 β 2x β 2 = 0
Check if it is factorable: a = 3, b = β2, c = β2
So b2 β 4ac = (β2)2 β 4(3)(β2) = 28. Not factorable!
Use QF, we get
x = β (β2) Β± ο 28
2(3)
=
2 Β± ο 28
6
=
2 Β± 2ο7
6
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
76. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
Example H. Solve 3x2 β 2x β 2 = 0
Check if it is factorable: a = 3, b = β2, c = β2
So b2 β 4ac = (β2)2 β 4(3)(β2) = 28. Not factorable!
Use QF, we get
x = β (β2) Β± ο 28
2(3)
=
2 Β± ο 28
6
=
2 Β± 2ο7
6
=
1 Β± ο7
3
Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
77. βbΒ±ο b2 β 4ac
2a
Solving 2nd Degree Equations ax2 + bx + c = 0
Example H. Solve 3x2 β 2x β 2 = 0
Check if it is factorable: a = 3, b = β2, c = β2
So b2 β 4ac = (β2)2 β 4(3)(β2) = 28. Not factorable!
Use QF, we get
x = β (β2) Β± ο 28
2(3)
=
2 Β± ο 28
6
=
2 Β± 2ο7
6
=
1 Β± ο7
3
ο» {1.22
β0.549
3. Use the quadratic formula (QF)
The roots for the equation ax2 + bx + c = 0 are
x =
b2 β 4ac is called the discriminant because its value
indicates what type of roots there are. Specifically,
if b2 β 4ac is a perfect square, we have fractional roots,
if b2 β 4ac < 0 there is no real roots.
78. Solving 2nd Degree Equations ax2 + bx + c = 0
Example I. Solve 3x2 β 2x + 2 = 0
79. Solving 2nd Degree Equations ax2 + bx + c = 0
Example I. Solve 3x2 β 2x + 2 = 0
Check if it is factorable: a = 3, b = β2, c = 2
So b2 β 4ac = (β2)2 β 4(3)(2) = β20
80. Solving 2nd Degree Equations ax2 + bx + c = 0
Example I. Solve 3x2 β 2x + 2 = 0
Check if it is factorable: a = 3, b = β2, c = 2
So b2 β 4ac = (β2)2 β 4(3)(2) = β20 and
οβ20 does not exist.
Hence it does not have any real number solution.
82. C. Solve the following equations by the quadratic formula.
If the answers are not real numbers, just state so.
1. x2 β x + 1 = 0 2. x2 β x β 1 = 0
3. x2 β 3x β 2 = 0 4. x2 β 2x + 3 = 0
5. 2x2 β 3x β 1 = 0 6. 3x2 = 2x + 3
Equations
83. (Answers to odd problems)
Exercise C.
1. No real solution 3. π₯ =
3
2
Β±
17
2
5. π₯ =
1
4
3 Β± 17
1. π₯ = β1, π₯ = 4 3. π₯ = β4, π₯ = β3 5. π₯ = β2, π₯ = 5
7. π₯ = 2 9. π₯ = 0, π₯ = 2 11. π₯ = Β±2, π₯ = 0
13. π₯ = β3, π₯ =
1
2
15. π₯ = 2(2 Β± 5)
Equations
1. x = Β±1 3. Doesnβt exist.
7. x = Β±1/2 9. x = Β±8 11. x = Β±β11/2
Exercise A.
5. x = Β±3/2
Exercise B.