Question

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

Answer 1

Answer:

$r(s(3))=7$

Step-by-step 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

$r(s(3))=(3-1)^{2} +2(3-1)-1$

$r(s(3))=(2)^{2} +2(2)-1$

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

$r(s(3))=7$