Find a Polar Equation for the Parametric Equations $$x = f _ { 1 } ( \theta ) , y = f _ { 2 } ( \theta )$$

Multiple Choice

Find a polar equation for the parametric equations.
$$x = f _ { 1 } ( \theta ) , y = f _ { 2 } ( \theta )$$

A) $y = x \tan \theta$
B) $r = \sqrt { \left[ f _ { 1 } ( \theta ) \right] ^ { 2 } + \left[ f _ { 2 } ( \theta ) \right] ^ { 2 } }$
C) $x ^ { 2 } + y ^ { 2 } = \left[ f _ { 1 } ( \theta ) \right] ^ { 2 } + \left[ f _ { 2 } ( \theta ) \right] ^ { 2 }$
D) $r = \left[ f _ { 1 } ( \theta ) \right] ^ { 2 } + \left[ f _ { 2 } ( \theta ) \right] ^ { 2 }$