Question

Formula for geometric progression

Answer 1

Answer:

Tn=ar^n-1

this is a correct formula

Answer 2

To find the nth term of a geometric sequence we use the formula:

where r common ratio

a1 first term

an-1 the term before the n th term

n number of terms

Sum of Terms in a Geometric Progression

Finding the sum of terms in a geometric progression is easily obtained by applying the formulas:

nth partial sum of a geometric sequence

sum to infinity

where Sn sum of GP with n terms

S∞ sum of GP with infinitely many terms

a1 the first term

r common ratio

n number of terms