write the equation of the parabola in vertex form. vertex (0,5) point (1,-2)

Question

write the equation of the parabola in vertex form. vertex (0,5) point (1,-2)

Answer 1

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

(h,k) = (0,5), so substituting:

y = ax^2 + 5

substitute (x,y) = (1,-2) in above to determine a:

-2 = a + 5

a = 7

y = 7x^2 + 5

Answer 2

f(x) = a(x - h)² + k

h = 0

k = 5

f(x) = ax² + 5

-2 = f(1)

-2 = a(1)² + 5

-2 = a + 5

a = -7

f(x) = -7x² + 5