Question

For the function y=-2x^2+4x+1, what are the coordinates of the vertex? Is it a maximum or minimum point? Hint: use the vertex/axis of symmetry formula for x. Show all work algebraically to earn full credit and use Desmos only to check your answer. (4 points)

Vertex: ___________________ Is this a Minimum or a Maximum? (circle/highlight one)

Answer 1

You can find vertex by using the formula:

\(AOS, f(AOS)\)
where \(AOS=\frac{-b}{2a}\) in the parabola \(y=ax^2+bx+c\)

To see if it is a minimum or maximum point, look at the sign of \(a\). If it is negative, the quadratic points downward, meaning that the vertex is a maximum. If it is positive, the quadratic points downward, meaning that the vertex is a minimum.

I assume you can type that in to desmos and review the answer

Answer 2

\(\color{#0cbb34}{\text{Originally Posted by}}\) @justjm
If it is positive, the quadratic points downward, meaning that the vertex is a minimum.


\(\color{#0cbb34}{\text{End of Quote}}\)

Correction:

If it is positive, the quadratic points upward, meaning that the vertex is (still) a minimum

Answer 3

Thanks, I'll go through it and come back to you.

Answer 4

when u quote yourself