- #1
Karol
- 1,380
- 22
Homework Statement
Homework Equations
First derivative=maxima/minima/vertical tangent/rising/falling
When f'(x)>0 → the function rises
The Attempt at a Solution
$$V=(15-2a)(8-2a)=4a^2-46a+120$$
$$V'=8a-46,~~V'=0\rightarrow a=5.75$$
But: ##~2a<8,~~V(a=4)=0##
So 5.75>4
And: ##~V''=8## so it holds water, it should be inverse.