Question

What is the area of the largest rectangle with lower base on the x-axis and upper vertices on the curve y=12-x^2?

Answer 1

Area of rectangle: LxW
so
(2x)(y)=2x(12-X^2)
then I would solve for x and substitute it back into the Area equation.

This is your area equation:
A =2x(12-x^2)
maximize by differentiating and setting equal to 0 then solve for x.