- #1
Karol
- 1,380
- 22
Homework Statement
Homework Equations
First derivative=maxima/minima/vertical tangent/rising/falling
Volume of a cone: ##~\displaystyle V=\frac{\pi}{3}r^2h##
The Attempt at a Solution
$$L=a^2+b^2~\rightarrow b^2=L-a^2$$
$$V=\frac{\pi}{3}a(L-a^2)$$
$$V'=\frac{\pi}{3}(L-3a^2),~V'=0:~a=\sqrt\frac{L}{3}$$
$$V=\frac{\pi}{3}\left[ \sqrt\frac{L}{3}\left( L-\frac{L}{3} \right) \right]$$
The answer should be:
$$V=\frac{2\pi L^3}{9\sqrt{3}}$$