What is the Cartesian form of #(-21,(81pi) /12)#?

1 Answer
Daniel L.
Nov 29, 2016

This is not a correct point in polar coordinates. See explanation.

Explanation:

The given pair does NOT represent a valid point in polar coordinates. According to the definition the first coordinate is a distance between the point and the origin, therfore it cannot be a negative number.

If a correct point #(r,varphi)# was given, then to calculate the Cartesian coordinates you would have to use:

#{(x=rcosvarphi),(y=rsinvarphi):}#

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