# Math Help - optimization

1. ## optimization

Find the dimensions and the area of the largest rectangle having its lower two corners on the x-axis and its two upper corners on the parabola .

I'm not sure how to approach this question, I can't even find the equation of constraint.

2. Originally Posted by shawli

Find the dimensions and the area of the largest rectangle having its lower two corners on the x-axis and its two upper corners on the parabola .

I'm not sure how to approach this question, I can't even find the equation of constraint.
did you sketch a picture?

$A = bh$

$A = 2xy$

$A = 2x(16-x^2)$

$0 < x < 4$

find $\frac{dA}{dx}$ and maximize.