`y = 3cos(x), [0,2pi]` Find the absolute extrema of the function on the closed interval.

Expert Answers
mathace eNotes educator| Certified Educator

Given: `y=3cos(x),[0,2pi]`

First find the critical x values of the function. To find the critical values, set the derivative equal to zero and solve for the x value(s). 





Plug in the critical values and the endpoints of the closed interval in to the original function.





Examine the f(x) values.

The absolute maximum is at the points  `(0,3) (2pi,3)`

The absolute minimum is at the point `(pi,-3)`