Question

The vertex of a quadratic function is located at (1, 4), and the y-intercept of the function is (0, 1). What is the value of a if the function is written in the form y = a(x – h)2 + k?

a=____

Answer 1

-3

Explanation:

right on edge

Answer 2

Using the values of h and k from the vertex in equation of parabola, we get:


`y=a(x-1)^(2) +4`

The y-intercept of the parabola is (0,1). Which means for x=0, y=1 for the given parabola. Using these values of x and y in above equation, we can find the value of a for the parabola.


`1=a (0-1)^(2) +4 \\ \\ 1-4=a \\ \\ a=-3`

The equation of parabola thus becomes:


`y=-3 (x-1)^(2) +4`