What is the polar form of $(4,-2)$ ?

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Answer 1 · 2016-01-21T22:55:05

$P_("(4,-2)")-> (r,theta)-> (2sqrt(5)color(white)(.),333.435^o) " polar"$

Tony B Tony B

$color(blue)("Length from origin to point (4,-2)"->r)$

$color(blue)(r=)sqrt(4^2+(-2)^2) =sqrt(20)=sqrt(2^2xx5)=color(blue)(2sqrt(5))$

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$color(blue)("Angular measure")$

$theta =360-tan^(-1)(2/4)$

$color(blue)(theta~~ 333.435^o)$ to 3 decimal places

Or in radians $theta~~5.82 " radians"$
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So $P_("(4,-2)")-> (r,theta)-> (2sqrt(5)color(white)(.),333.435^o) " polar"$

What is the polar form of (4,-2)(4,-2)?