First, understand the concept of a turning point (zero gradient, implying first derivative is zero at the turning point)How do we differentiate exponentials ( if f(x) = e^g(x) then f'(x) = g'(x)*e^g(x) ) Okay, now how do we differentiate (sin2x) (=g(x) in this example)Chain rule & recap how to differentiate trig (we require familiarity with d(sinx)/dx = cosx)Figure out f'(x) and then set to equal zeroSolve equation to find coordinates of turning pointsOf course, use whiteboard and step by step lines of working to guide to answer