Question

Which quadratic function is represented by the graph?

y = 0.5(x + 2)2 + 4
y = 0.5(x + 3)2 – 0.5
y = 0.5(x – 3)2 – 0.5
y = 0.5(x – 2)2 + 4

Answer 1

Answer: C

Explanation:

The equation of a parabola in vertex form is

y = a(x - h)² + k

where (h, k) are the coordinates of the vertex and a is a multiplier

Here (h, k) = (3, - 0.5), thus

y = a(x - 3)² - 0.5

To find a substitute either of the x- intercepts into the equation.

Using (4, 0), then

0 = a(4 - 3)² - 0.5 = a - 0.5 ( add 0.5 to both sides )

a = 0.5

y = 0.5(x - 3)² - 0.5 ← equation of quadratic function