Recent content by noelwolfe

Got it. Thanks!

I'm sorry, I still don't know--I'm not aware of a "simple" solution to tan(x)=9/2. How would I go about finding the solution?

Homework Statement Determine all x in [-pi/2, pi/2] at which the graph has horizontal tangents. Homework Equations 1.) f'(x)= 9cos(x)-2sin(x) 2.) f'(x)= -5csc(x) (5cot(x)-csc(x)) The Attempt at a Solution 1.) 9cos(x)=2sin(x) 9/2=sin(x)/cos(x) 9/2=tan(x) and then I'm...