How do you convert #r=5costheta# into rectangular equations?

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Answer 1 · 2017-01-20T08:20:39

#x^2+y^2-5x=0#

I take it that this means converting to Cartesian form. For conversion of Polar to and from Cartesian we use the eqns.

#r^2=x^2+y^2#

#x=rcostheta#
#y=rsintheta#

for
#r=5costheta#

multiply both sides by #r#

#r^2=5rcostheta#

using the above conversion eqns.

#x^2+y^2=5x#

#x^2+y^2-5x=0#