Which of the following represents the th term of a geometric progression with first…

MATHEMATICS · Single correct · A Level · Mathematics · Sequences and series · Sequences and series

Problem

Which of the following represents the

n

th term

(a_n)

of a geometric progression with first term

a

and common ratio

r

? (a)

a + (n-1)r

(b)

\displaystyle \frac{a(1-r^{\,n})}{1-r}

(c)

ar^{\,n-1}

(d)

ar^{\,n}