anyway, its probably really simple, but the question is;

Use differentiation to show that the function

**f(x) = 5sin x**has a maximum turning value of 5 at

**x=pi/2**and a minimum value of -5 at

**x=pi**

Any help would be appreciated. Thanks

oh, so far i have f'(x) = 5cosx

sp's occur where f'(x) = 0

=> 5cosx =0

i just dunno where to go from there