How do you convert $r=-4cos(theta)$ into cartesian form?

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Answer 1 · 2016-06-05T05:43:56

$x^2+y^2+4x=0$

To convert polar form of equation to Cartesian form, one can use $rcostheta=x$ and $rsintheta=y$ . From this we also get $r^2=x^2+y^2$ .

Hence, $r=-4costheta$ can be written as

$r^2=-4rcostheta$ or

$x^2+y^2=-4x$ or

$x^2+y^2+4x=0$

How do you convert r=-4cos(theta)r=-4cos(theta) into cartesian form?