# Max value of trigonometric function

• January 7th 2011, 12:21 PM
hejmh
Max value of trigonometric function
Decide the x-value which is Max value of the function y=4sin(x)+3cos(x) in 0<=x<=2

Thanks for helping.
• January 7th 2011, 12:33 PM
dwsmith
Endpoints (0,3) and (2,2.3887)

1st derivative $\displaystyle y'=4\cos{x}-3\sin{x}=0\Rightarrow \frac{4}{3}=\tan{x}$

Solve the equation for rel. maxes between [0,2] if there are any.