(578,#19) Find the area of the region enclosed by one loop of the curve (inner loop).

Solution:

To determine the boundaries of the inner loop note:

The curve starts at (1,0)

continues on to (3,Pi/2)

continues on to (1,Pi)

reaches the origin for the first time at 7Pi/6

reaches the highest point of the inner loop at 3Pi/2

returns to the origin at 11Pi/6

and then returns to the starting point (1,2Pi)

Therefore, the entire inner loop starts at 7Pi/6 and ends at 11Pi/6. By use of symmetry, we can evaluate the function from and multiply by 2 to get the area of the entire loop.

Maple code

by:sh