PLEASE HELP ME IF YOU COULD, CAN YOU TELL ME HOW YOU FOUND THE ANSWER??

The graph shows the distance y, in inches, a pendulum moves to the right (positive displacement) and to the left (negative displacement), for a given number of seconds x. how many seconds are required for the pendulum to move from its resting position and return? enter your answer in the box.

How to do this , and can some one explain

Need asap. solve for the following inequality