Question

A quadratic function has a vertex of (0,7) and passes through the point (2, 3). Which of

the following is the equation of the graph of the quadratic function?

Answer 1

Y = -2X + 7

Explanation:

Y = a(x-h)^2 + k

From (h,k) h = 0 k = 7 x = 2 y = 3

3 = a(2-0) + 7

3 = 2a - 0 + 7

Collect like terms

2a = 3 - 7

2a = -4

Divide both sides by 2

2a/2 = -4/2

a = -2

y = a(x-h) + k

y = -2(x-0) + 7

y = -2x + 0 + 7

y = -2x + 7 or

y + 2x - 7 = 0