Can someone help me with number 5 :((

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.

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

Which expression shows the sum of the polynomials with like terms grouped together