Vertex and roots of a quadratic

For a parabola, Desmos marks the vertex (highest or lowest point) and the $x$-intercepts (roots) with grey dots.

Example: for $y = -2x^2 + 8x - 6$, click the top of the curve: the vertex is $(2, 2)$, so the maximum value is $2$. The roots are $x = 1$ and $x = 3$.

• Sum of the roots = $1 + 3 = 4$, and the vertex sits halfway between them, at $x = 2$.
• No $x$-intercepts means no real solutions (negative discriminant).
• The $y$-intercept is the constant term, here $-6$.

On the test: "maximum value", "minimum value", "vertex", and "zeros of the function" are all one click away.