The vertex of this parabola is at (5, -4). Which of the following could be its equation?

Question

A. y = 2(x + 5)2 + 4

B. y = 2(x - 5)2 + 4

C. y = 2(x + 5)2 - 4

D. y = 2(x - 5)2 - 4

Answer 1

Case A: 2*(5 + 5)^2 + 4 = 2*(10)^2 + 4 = 2*100 + 4 = 204 does not equal -4

Case B: 2*(5 - 5)^2 + 4 = 2*(0)^2 + 4 = 2*0 + 4 = 4 does not equal -4

Case C: 2*(5 + 5)^2 - 4 = 2*(10)^2 - 4 = 2*100 - 4 = 196 does not equal -4

Case D: 2*(5 - 5)^2 - 4 = 2*(0)^2 - 4 = 2*0 - 4 = -4

 

The answer is D.

Answer 2

The answer is D