When will the motion of a simple pendulum be simple harmonic?

Answer the following questions : The motion of a simple pendulum is approximately simple harmonic for small angle oscillations. For larger angles of oscillation, a more involved analysis shows that T is greater than 2pisqrt(l/g) . Think of a qualitative argument to 9 appreciate this result

What is simple harmonic motion and prove a simple pendulum oscillates simple harmonically?Also find a relation for its frequency.

Why are vibrations of a simple pendulum damped?

How will the period of a simple pendulum change when its length is doubled?