Question 438253
{{{x^2 + y^2 = (a*sin(theta) - b*cos(theta))^2 + (a*cos(theta) + b*sin(theta))^2

= a^2sin^2(theta) - 2ab*sin(theta)cos(theta) + b^2cos^2(theta) +
a^2cos^2(theta) + 2ab*sin(theta)cos(theta) + b^2sin^2(theta)

=a^2 + b^2}}}