Skip to content

The curve C is defined parametrically by

x=3cos⁡(2t)+sin⁡(2t)y=t2−4

for −π<t<π.

The curve is bound by a rectangle whose sides lie tangent to C and parallel to the axes.

Find the area of the rectangle.


Focus on finding the largest and smallest possible values of y=t2−4. You might even find it most convenient to plot the curve y=t2−4 with the horizontal axis as t and the vertical axis as y.

The smallest value of y tells you the lowest point on the curve, and the largest value of y tells you the highest.


To find the leftmost and rightmost points on the curve, you need to find the largest and smallest values of x. You can use dxdt=0, or you can convert x into harmonic form.


Give your answer to 3 significant figures.