Use the Extreme Value Theorem:
If a function f(x) is continuous on a closed interval [ a, b], then f(x) has both a maximum and minimum value on [ a, b]
First, find all critical points in the given interval by taking the derivative of f(x) wrt x, setting it to zero, and solving for x. Next evaluate the value of the function at these critical points. Use only those critical points in the specified interval (between 0 and pi/2).
Next, evaluate the value of the function at the endpoints of the interval [0, pi/2]
The largest function value from the previous two steps is the maximum value, and the smallest function value is the minimum value of the function on the given interval.
