## twirlere Group Title f(x)=2secx+tanx 0<x<2pi I'm finding critical points. one year ago one year ago

1. myko

You mean where 1º derivative is 0?

2. twirlere

? I don't understand. I took the derivative and got: f'(x)=2secxtanx+secx2. Then I took out secx: secx(2tanx+secx). And I know I have to set it equal to 0 and solve, I'm having trouble with inside the parentheses though.

3. myko

write it like this: $\frac{1}{cosx}(\frac{2sinx}{cosx}+\frac{1}{cosx})=0$ now muñtiply bouth sides by cosx to get: 1(2sinx+1)=0 and solve for x

4. myko

ok?

5. twirlere

Okay! thanks!