Question

Find the first 4 terms of the geometric sequence a1=40 and r=0.5

Answer 1

The first four terms of a GP are, {40, 20, 10, 5}.

Explanation:

The nth term of a geometric progression is:
`T_(n)=a_(1)* r^(n-1)`

Here a₁ = first term and r = common ratio.

Given: a₁ = 40 and r = 0.50

The 1st term is,

`T_(1)=a_(1)* r^(1-1)=a_(1)=40`

The 2nd terms is,

`T_(2)=a_(1)* r^(2-1)=a_(1)=40* (0.50)^(1)=20`

The 3rd term is,

`T_(3)=a_(1)* r^(3-1)=a_(1)=40* (0.50)^(2)=10`

The 4th term is,

`T_(4)=a_(1)* r^(4-1)=a_(1)=40* (0.50)^(3)=5`

Thus, the first four terms of a GP are, {40, 20, 10, 5}.