Given the arithmetic sequence a_n = 6 4(n 2), what is the domain for n [Solved]

For the first question

For the first question

S(n) = 0.5n(2 [a_(1)] (n 1)d)
S_(26) = 0.5(26)(2(8) (25)7)
S_(26) = 13(16 175)
S_(26) = 13(191)
S_(26) = 2483

For the second question

S(n) = 0.5n(2 [a_(1)] (n 1)d)
S_(26) = 0.5(26)(2(8) (25)7)
S_(26) = 13(16 175)
S_(26) = 13(191)
S_(26) = 2483

For the third question, a_(1) = 8, n = 26 and d = 7

a_(n) = [a_(1)]r^(n-1)
a_(4) = [a_(1)]r
64 = -4096r
r = -1/64
r = -1/4

a_(n) = [a_(1)]r^(n-1)
a_(4) = [a_(1)]r
64 = -4096r
r = -1/64
r = -1/4

a_(7) = [a_(1)]r^6
a_(7) = -4096(-1/4)^6
a_(7) = 1

Therefore

S(n) = 0.5n(2 [a_(1)] (n 1)d)
S_(26) = 0.5(26)(2(8) (25)7)
S_(26) = 13(16 175)
S_(26) = 13(191)
S_(26) = 2483

Hope this helps.

This post is last updated on hrtanswers.com at Date : 1st of September – 2022