Converting Cartesian coordinates into polar coordinates.

(x,y) = (3,-5)
(r,$\theta$) = ($\sqrt{34}$,???)

$r=\sqrt{(3)^2+(-5)^2}=\sqrt{9+25}=\sqrt{34}$
$\theta = tan^{-1}(\frac{(-5)}{(3)})=???$

My answer needs to be in radians an I'm not seeing how the unit circle is going to be of much help here. It's not a nice angle like $\frac{\pi}{2}$, $\frac{\pi}{3}$, $\frac{\pi}{4}$, $\frac{\pi}{6}$, or $\pi$

Question

Converting Cartesian coordinates into polar coordinates.

(x,y) = (3,-5)
(r,$\theta$) = ($\sqrt{34}$,???)

$r=\sqrt{(3)^2+(-5)^2}=\sqrt{9+25}=\sqrt{34}$
$\theta = tan^{-1}(\frac{(-5)}{(3)})=???$

My answer needs to be in radians an I'm not seeing how the unit circle is going to be of much help here.  It's not a nice angle like $\frac{\pi}{2}$, $\frac{\pi}{3}$, $\frac{\pi}{4}$, $\frac{\pi}{6}$, or $\pi$

anonymous · Answer

-59.036

anonymous · Answer

I don't think it's going to let me take it as a decimal though, especially since is a irrational, non-repeating decimal: http://www.wolframalpha.com/input/?i=tan^%28-1%29+%28-5%2F3%29

anonymous · Answer

it will be most probably  $$-\pi/3$$

anonymous · Answer

I was hoping Wolf would help me convert, but alas it appears not...

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