PSAT Math Multiple-Choice Question 592: Answer and Explanation

Question: 592

What will happen to the graph of y = x² in the xy-plane if it is changed to

y = (x + 8)² + 4?

• A. It will shift to the left 8 units and shift up 4 units.
• B. It will shift to the right 8 units and shift up 4 units.
• C. It will shift to the left 8 units and shift down 4 units.
• D. It will shift to the right 8 units and shift down 4 units.

Correct Answer: A

Explanation:

(A) When you add a number to the x-value itself, the function shifts to the left by that number of places. When you add a number to the function as a whole, the function shifts upward by that number of places. Since 8 is added to the x-value itself and 4 is added to the function as a whole, the function shifts to the left 8 units and shifts up 4 units.