Derivatives of Trig Functions: Applications

2. For the equation y = 3 cosx, find the minimum and maximum points.

Take the derivative, set it equal to zero, and solve.

dy/dx = -3 sinx = 0

x = 0.pi, 2pi, 3pi, etc.

Maximum points: 0, 2pi, 4pi, etc

Minimum points: pi, 3pi, 5pi, etc