A parabola has a vertex at (0, –1) and passes through the point (2, 2). Which of the following is the equation of this parabola in the form

Respuesta :

for vertex at (h,k)
the equation is
y=a(x-h)^2+k

for vertex at (0,-1)
equation is
y=a(x-0)^2+(-1) or
y=ax^2-1
find what a is

(2,2)
x=2
y=2
2=a(2^2)-1
2=a(4)-1
add 1
3=a(4)
divide both sides by 4
3/4=a

the equation is
y=3/4x^2-1