Given the parabola below, find its equation in vertex form. The points represent the vertex (-1,11) and y-intercept (0,8).

Answer 1

vertex (-1, 11) y intercept (0,8) what's the parabola equation?

in vertex form the equation is y = a(x+1)^2 + 11

plug in (0,8)

8 = a + 11

a = -3

the equation is

y =

f(x) = -3(x+1)^2 + 11 in vertex form with vertex (-1,11)

Answer 2

know parabola is shifted one unit negative for x (vertex at x=-1)

equation must be y=A(x+1)²+B,,,,recall shift negative is positive addition to x

x=0, y=8, 8=A+B

x=-1 y=11, 11=B

A=-3

answer is y=-3(x+1)²+11

Answer 3

The vertex form is:

y = a(x-h)² + k

where (h,k) specifies the location of the vertex and a is a constant. In your case, (h,k) = (-1,11) so just substitute those values into the equation:

y = a(x-h)² + k

y = a(x-(-1))² + 11

y = a(x+1)² + 11

To find the value of the constant, a, plug in the given point (0,8):

y = a(x+1)² + 11

8 = a(0+1)² + 11

8 = a + 11

-3 = a

Final equation:

y = -3(x+1)² + 11