- #1
Justabeginner
- 309
- 1
Homework Statement
I have to find the relative maximum, so I'm going to set the second derivative to zero and solve. But, this is where I'm stuck.
Homework Equations
f"(x)= (x^2-4)(sin(2x)) - (2x)(1+cos^2(x))/ ((1+cos^2(x))^2) [The entire equation is divided by the ((1+cos^2(x))^2)]
The Attempt at a Solution
(x^2-4)(sin(2x)) - (2x) (1+cos^2(x))= 0
(x^2-4) (sin(2x)) = (2x) (1+cos^2(x))
I feel like an idiot, because I can't get past this point ^. Any help is appreciated. Thank you!