Question

What is the vertex in the quadratic function y= -4x^2+8x-3? Write answer as an ordered pair.

Answer 1

Well you have an equation in the form

\[\large ax^2 + bx + c\]

To find the x-coordinate of the vertex...you use the equation

\[\large \frac{-b}{2a} \]

What do you get when you do that?

Answer 2

y = -4x^2+8x-3
y = -4 (x^2 - 2x)-3
y = -4 ((x - 1) ^2 -1)-3
y = -4 (x - 1) ^2 +1
Vertex (1, 1)

Answer 3

no reason to change form when you have -b/(2a)

Answer 4

True, but you should practice you algebra instead of memorizing esp in the beginning. This form gives more than just vertex