Use the vertex (h,k) and a point on the graph (x,y) to find the equation of each quadratic function in standard form.

Question

h,k= -3,-5

x,y= 6,-6

Answer 1

- 6 = a(x+3)^2 -5

-1 = a(6+3)^2 = a(9)^2 = 81a

a = -1/81

BUT now you need to take the vertex form and convert it standard form:

Ax^2 + Bx + C = 0

Multiply out and use algebra to obtain the above form.

Answer 2

f(x) = a(x + 3)² - 5

Substitute x = 6 and f(x) = -6, and solve for a