Write the explicit formula for the geometric sequence.

Question

0

2077

1

+16

Write the explicit formula for the geometric sequence.

a₁ = -5 a₂ = 20 a₃ = -80

+23246

+5

Best Answer

An explicit formula for a geometric sequence is: t_n = t₁ · r^{n - 1}

where t₁ is the first term = -5 r is the common ratio = -4

t_n is the n^th term (leave it in the formula) n is the number of the term (leave it in the formulat)

so the formula is t_n = -5 · (-4)^{n - 1}<--- answer!

You can find the common ratio by dividing the second term by the first term: 20 ÷ -5 = -4

geno3141 Jul 15, 2015

geno3141 · Answer 1 · 2015-07-15T12:29:13

An explicit formula for a geometric sequence is: t_n = t₁ · r^{n - 1}

where t₁ is the first term = -5 r is the common ratio = -4

t_n is the n^th term (leave it in the formula) n is the number of the term (leave it in the formulat)

so the formula is t_n = -5 · (-4)^{n - 1}<--- answer!

You can find the common ratio by dividing the second term by the first term: 20 ÷ -5 = -4