Chapter 10 - Conics, Parametric Equations, and Polar Coordinates - 10.4 Exercises - Page 722: 33

Rectangular equation: $y^2 + x^2 = 16$ Graph:

**Remember: $cos^2(θ) + sin^2(θ) = 1$, $rcos(θ) = x$ and $rsin(θ) = y$ $r = 4$ $r^2 = 16$ $(1)r^2 = 16$ $(sin^2( θ ) + cos^2( θ ))r^2 = 16$ $r^2sin^2( θ ) + r^2cos^2( θ )= 16$ $y^2 + x^2 = 16$