Question

The function P(x)=x2+2x−1 is dilated by the function I(x)=P(−2x).Which function rule represents I(x)?

Answer 1

SOLUTION

We have

$\begin{gathered} P(x)=x^2+2x-1 \\ I(x)=P(-2x) \\ So,\text{ we will substitute } \\ I(x)=P(-2x)\text{ into } \\ P(x)=x^2+2x-1 \end{gathered}$

We have

$\begin{gathered} P(-2x)=(-2x)^2+2(-2x)-1 \\ =4x^2-4x-1 \\ I(x)=4x^2-4x-1 \end{gathered}$

Hence the last option is the answer