Question

What is the equation of the graph below?

A. y = − (x − 3)^2 + 1
B. y = − (x + 3)^2 + 1
C. y = (x − 3)^2 − 1
D. y = (x + 3)^2 − 1

Answer 1

D

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, - 1 ) , then

y = a(x - (- 3) )² + (- 1)

y = a(x + 3)² - 1

to find a substitute the coordinates of any other point on the graph into the equation.

using (- 2, 0 )

0 = a(- 2 + 3)² - 1

0 = a(1)² - 1

0 = a - 1 ( ad 1 to both sides )

1 = a

then

y = (x + 3)² - 1 ← equation of graph