Practice!

Sample Problem

Which of the following graphs is an accurate representation of f(x)=-1/4cosx?

Solution

The graph of f(x)=-1/4cos x has a period of 2π and an amplitude of 1/4.

 The range of this graph is [-1/4,1/4] and f(0)=-1/4cos(0)=-1/4 so the graph starts at (0, -1/4).