Hey guys.

For the chapter on max/min, I am really having no problem calculating things that lead to finding the max and min values. I seem to only reach a roadblock after you find the derivative of something involving trig. For example:

f(x)=sin(2x) + cos(x) on interval 0 </ x </ pi

So, finding derivative:

f'(x)= 2cos2x - sinx

I'm pretty bad with trig (detrimental, I know), so I don't really know how to solve for x. How can you find the critical values with such a function? A step by step explanation process would be greatly appreciated!