For all values of y, let y☆ be defined by y☆ = y^2 - 1. Which of the following is equal to (y☆)☆?

Test Preparation SAT Preparation
1

<p>(A) y^4 - 1
(B) y^4 - y^2 - 1
(C) y^4 + y^2 - 1
(D) y^4 - 2y^2
(E) y^4 - 2y^2 + 1</p>

2

<p>(y^2-1)^2-1 = y^4-2y^2+1-1 = y^4-2y^2</p>

3

<p>Thank you!!!</p>

4

<p>What’s the source of these questions?</p>

5

<p>Sorry for the late reply I just now noticed this! These questions come from Testmaster’s SAT book!</p>