Find an explicit rule for the nth term of the sequence. -4, -8, -16, -32, ...

Answer 1

The sequence is -4,-8,-16,-32.......

The sequence is geometric, since each successive term can be obtained by multiplying the previous term by 2.

So common ratio r = 2.

First term , a = -4

Calculate the nth term of the sequence by using the formula.

tn =a r^n-1

    =(-4)(2)^n-1

Therefore, the nth term of the sequence is (-4)(2)^n-1