Question

Let a*pi be the area of the region bounded by the curve defined by the parametric equations x=10cos2t, y=10sin2t where 0<=t<=2pi. What is a?

Answer 1

This is just a circle of radius 10.

Note that as t varies from 0 to 2pi, the curve is traced twice.

As usual, area = ∫y dx
just plug in your values for x and y and the value should drop out.