Which graph shows a function whose inverse is also a function?

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.

If a flying disk is 139 meters in the air and travels at an average of 13 m/s how long is it in the air

Is a square always, sometimes, or never a parallelogram