PSAT Math Multiple-Choice Question 742: Answer and Explanation

Question: 742

If the line given by the equation y = 4x + 7 is reflected about the x-axis, what will be the graph of the resulting function?

• A.
• B.
• C.
• D.

Correct Answer: A

Explanation:

(A) Multiply both the slope and the y-intercept of the given line by -1 to get the reflection of the line. For y = 4x + 7, this is the equation y = -4x -7.

The general rule to find the reflection of a function f(x) across the x-axis is that the reflection is -f(x).