Explore a diverse range of topics and get answers from knowledgeable individuals on IDNLearn.com. Join our Q&A platform to access reliable and detailed answers from experts in various fields.

7. Given an arithmetic sequence, find a26if a4 = 71 and a32 = 1. 8. Given a geometric sequence, find az ifa1 = 729 and a2 = – 243.

Sagot :

Arithmetic sequence

a= 26

a4 = 71

a32 = 1.

an = a1 + (n-1)d

a4 = a1 + (3)*d

71 = a1 + (3)*d (I)

a32 = a1 + (31)*d

1 = a1 + 31 d (II)

to find a1 and d we subtract (II)- (I)

1 = a1 + 31 d (II)

-( 71 = a1 + (3)*d) (I)

________________

-70 = 0 28 d

-70 = 28 d

d= -70/ 28

d= -5/2

Replacing d in (I)

71 = a1 - (3)(5/2)

a1= 71 + (3)(5/2)

a1= 78.5

The arithmetic sequence is

an = a1 + (n-1)d

an = 78.5 + 2.5 (n-1)

Verifying

a4 = 78.5 - 2.5 (3) = 78.5 -7.5= 71

a32 = 78.5 +2.5 (31) =78.5 -77.5 = 1

a26 = 78.5 + 2.5 (25) = 78.5 - 62.5 = 16

Give me some minutes

______________________

Answer

a26 = 16

We value your participation in this forum. Keep exploring, asking questions, and sharing your insights with the community. Together, we can find the best solutions. Find the answers you need at IDNLearn.com. Thanks for stopping by, and come back soon for more valuable insights.