Question

Find the function of a graph in vertex form, whose

vertex is (-1,5) and passes through the point (2, -3)

Answer 1

y = -⁸/₉(x + 1)² +5

Explanation:

y = a(x - h)² + k - vertex form of quadratic function with vertex (h, k)

y = a(x - (-1))² + 5 - vertex form of quadratic function with vertex (-1, 5)

y = a(x +1)² + 5

graph goes through (2, -3) so if x=2 then y =-3

-3 = a(2+1)² + 5

-3 -5 = a×3² + 5 - 5

-8 = 9a

a = -⁸/₉

So the equation of the function:

y = -⁸/₉(x + 1)² + 5