Question

Given r(x) = x square +2x -1 and s(x) = x-1 what is the value of r(s(3))

Answer 1

`r(s(3))=7`

Explanation:

we have

`r(x)=x^(2) +2x-1`

`s(x)=x-1`

we know that

The function composition is equal to

(r ∘ s )(x) = r(s(x))

In the function r(x) substitute the variable x by the function s(x)

so

`r(s(x))=(x-1)^(2) +2(x-1)-1`

For x=3

substitute the value of x=3 in the function composition

`r(s(3))=(3-1)^(2) +2(3-1)-1`

`r(s(3))=(2)^(2) +2(2)-1`

`r(s(3))=4+4-1`

`r(s(3))=7`