Parabola of a Function

Question

Find b and c so that y=−13x2+bx+c has vertex (2,6). 

Answer 1

Answer 2

Since the x-coordinate of the vertex is 2, the axis of symmetry is the line x=2.

One way to find the equation of the axis of symmetry is to use the formula x = -b/2a.

That means -b/2(-13) = 2.

-b = -52

b=52

To find c , let x = 2 and y = 6 when the function is written as:

y = -13x²+52x + c.

desmos.com/calculator/inthadqfyv