How do you change the polar equation $r = 3 cos θ$ $r=3costheta$ into rectangular form?

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Answer 1 · 2016-10-27T16:56:10

$x^{2} + y^{2} = 3 x$ $x^2+y^2=3x$

for polars/rectangular

$x^{2} + y^{2} = r^{2}$ $x^2+y^2=r^2$

$x = r cos θ$ $x=rcostheta$
$y = r sin θ$ $y=rsintheta$

$r = 3 cos θ$ $r=3costheta$ -----(1)

$\times$ $xx$ (1) by $r$ $r$

$r^{2} = 3 r cos θ$ $r^2=3rcostheta$

$x^{2} + y^{2} = 3 x$ $x^2+y^2=3x$

How do you change the polar equation r=3costhetar=3cosθr=3costheta into rectangular form?