Question

What is the equation written in vertex form of a parabola with a vertex of (–1, 8) that passes through (1, 0)?

Answer 1

Answer:

y = -2(x + 1)^2 + 8

Step-by-step explanation:

The equation of a parabola can be written in the form;

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

where a is the multiplier (h,k) is the vertex

so h = -1 and k = 8

Plug in these values

y = a(x + 1)^2 + 8

So to get the value of a, we use the point where the parabola passes through which is the point (1,0)

Simply substitute the values of x and y

0 = a(1 + 1)^2 + 8

0 = a(2)^2 + 8

-8 = 4a

a = -8/4

a = -2

So therefore the equation of the parabola is ;

y = -2(x + 1)^2 + 8