The graph below is one complete cycle of the graph of an equation containing a trigonometric function. Find an equation to match the graph. If you are using a graphing calculator, graph your equation to verify that it is correct.
B)
C)
D)

Question

The graph below is one complete cycle of the graph of an equation containing a trigonometric function. Find an equation to match the graph. If you are using a graphing calculator, graph your equation to verify that it is correct.  ​
B)​ 
C)​ 
D)​

Quizplus · Accepted Answer

The graph starts at its maximum at x=0, so it is a cosine function. The amplitude is 2, so the coefficient of cosine is 2. The period is 4, so the coefficient of x inside the cosine function is 2π/4 = π/2. Finally, the graph is shifted to the right by π/2 units, so the equation of the cosine function is y = 2cos(π/2(x-π/2)). Graphing this equation on a calculator confirms that it matches the given graph.

The Graph Below Is One Complete Cycle of the Graph