What is the Cartesian form of $(49,(-7pi)/4)$ ?

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Answer 1 · 2017-02-24T16:46:33

$(49,(-7pi)/4)$ in Cartesian coordinates is $(49/sqrt2,49/sqrt2)$ or $(34.65,34.65)$

Polar coordinates $(r,theta)$ in Cartesian form is $(rcostheta,rsintheta)$

Hence, $(49,(-7pi)/4)$ in Cartesian coordinates is

$(49cos((-7pi)/4),49sin((-7pi)/4))$

or $(49cos((-7pi)/4+2pi),49sin((-7pi)/4+2pi))$

or $(49cos(pi/4),49sin(pi/4))$

i.e. $(49xx1/sqrt2,49xx1/sqrt2)$

or $(49/sqrt2,49/sqrt2)$

i.e. $(34.65,34.65)$

What is the Cartesian form of (49,(-7pi)/4)(49,(-7pi)/4)?