This slide focuses on finding the value of the first term given any two values of an arithmetic progression.

1. ARITHMETIC
SEQUENCE
Finding the value of a11
Solomon Hippocrates S. Flores
E. Rodriguez Vocational High School

2. ANSWER TO Assignment
1. n = 46
2. d = 1
3. n = 72

3. Give the first three terms in the arithmetic
sequencegiven the commondifference.
1) a1 = 2, d = 2

4. 2) a1 = 2, d = -2

5. 3) a1 = -11, d = 7

6. 4) a1 = -3, d = -2

7. 5) a1 = 24, d = -6

8. 6) a1 = 36, d = -2

9. 7) a1 = -1, d = 4

10. 8) a1 = ½, d = 1

11. 9) a1 = 8, d = - ½

12. 10) a1 = 3x + 5, d = x - 2

13. Mario is a jeepney driver plying the route from
Fairview to Quiapo. Every day he passes by the
gasoline station to buy diesel gas for his jeepney. With
the increasing prices of gasoline and diesel, he wants
to monitor the number of liters of diesel he uses every
day.

14. So, every day, he
takes note of the
number of liters of
diesel his jeep uses
up.
It so happens that Mario lost his record. The
only ones that he can remember is the amount
used on Wednesday, his jeep used up 8 liters of
diesel gas and on Saturday, it used up 9.5 liters of
diesel gas. How many liters of diesel gas do you
think will he buy at the start of the week {Monday)
and everyday there after?

15. The above activity illustrates a sequence
where the first term is missing while any two of
the arithmetic progression is given.
The general formula for the arithmetic
sequence
can be used to solve such situations.

16. Consider the following:
1. If the 3rd term of an arithmetic
sequence is 8 and the 16th term is 47,
find a1.

17. 2. Find the first term of the
arithmetic sequence if a12 = 47 and
d = 3.

18. 3. If the 3rd term in the arithmetic
sequence is 2 and the
15th term is -34. What is a1?
Give the next five terms.

19. Solve the following.,
,
1. The 3rd term of an arithmetic sequence is 8 and 7th
term is 20, find the first term.
2. Find the first term of the arithmetic sequence if
a100 = 702 and d = 7.
3. The 10th and 12th terms of an arithmetic sequence
are 11 and 14, respectively. Find d and a1.
4. If the 6th term of an arithmetic sequence is 27 and
the 12th term is 48, find the first term.
5. Find the first term of an arithmetic sequence whose
34th term is -39 and 50th term is -61.

20. VALUES INTEGRATION
A sick child is given a
dose of medicine every 8
hours. If the mother gave
the first dose at 8am on
Monday, how many times
was the medicine given
until Sunday evening?
Write the sequence
representing the time the
mother gave the medicine
to her sick child.

21. Solve the following..,
,
1. The 12th term is -7 and the 25th term is 6. Find a1.
2. The last term of the arithmetic sequence is 207, the
common difference is 3 and the number of terms is
14. What is the first term?
3. What are the first four terms in the sequence if the
third term is 4 and the fifth term is 20.
4. The 14th term in an arithmetic sequence is 98 and
the 15th term is 105. Find a1.
5. If the 16th term of an arithmetic sequence is 48 and
the common difference is 3, find the first term.

22. Assignment
,
,
1. Find the first five terms in the arithmetic
sequence given a3 = 2 and a5 = 10.
2. What are the first five terms of an
arithmetic sequence whose 9th term is 16
and 40th term is 47?
3. Find the arithmetic sequence of 6 terms
if the first term 2/3 is and the last term is
22/3.

23. Thank you!