Answer:
Below.
Step-by-step explanation:
We apply the quotient rule:
dy/dx = ( tanx * 3x^2 - x^3 * sec^2x) / (tan^2 x)
= x^2( 3tanx - xsec^2x) / tan^2x
That's a right triangle with hypotenuse 3000 and the height y is the side opposite the elevation angle of 15 degrees.

We can actually compute

exactly but I won't bother.
Answer:
height is 4 in
Step-by-step explanation:
total area 72
divide area by base length
72/18= 4
72 total area
18 base length
4 height