what is the x-intercepts and the vertex?

Question

An artist drew a rainbow mural on a a school cafeteria wall. it’s outer boundary can be represented by a parabola with the equation, y=-x2+6x, where y the height of the outer boundary of the rainbow in feet and a is the width in feet

Answer 1

Vertex (3,3)...differentiate and set derivative to 0, solve for x

X-intercepts: (0,0) and (0,6)...solve equation for x by factoring.