Question

Find the 40th term of the sequence 2, -12, 72, ...

Answer 1

apply 40th term = a*[r^(n-1)]....n = 40

Answer 2

an = a1 * r^(n-1)
n = number of term to find = 40
a1 = first term = 2
r = common ratio = -6
now we sub
a40 = 2 * -6 ^ (40 - 1)
a40 = 2 * (-6 ^ 39)
a40 = 2 * -2.23
a40 = - 4.46