How do you convert r = -2cos(θ) – 2sin(θ) into cartesian mode?

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Answer 1 · 2018-04-19T13:06:33

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

Remember that:

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

#rcos(theta)=x#

#rsin(theta)=y#

We have:

#r=-2cos(theta)-2sin(theta)#

Note here that we are just missing the #r#.

Multiply both sides by #r#.

#=>r^2=-2rcos(theta)-2rsin(theta)# We can now substitute.

#=>x^2+y^2=-2x-2y#

You can simplify this from here on, depending on what your teacher wants. (Turn this to a circle relation #(x-h)^2+(y-k)^2=r^2#)