I'm converting -3,4 to polar.

I have come up with r = +/ 5

And tan (x) = -4/3

When I do x = arctan (-4/3)

in my calculator I get -.927 but the book has 2.214

Why?

Thanks.

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- Jun 15th 2013, 06:11 AMminneola24Converting to polar (easy)
I'm converting -3,4 to polar.

I have come up with r = +/ 5

And tan (x) = -4/3

When I do x = arctan (-4/3)

in my calculator I get -.927 but the book has 2.214

Why?

Thanks. - Jun 15th 2013, 06:55 AMPlatoRe: Converting to polar (easy)
- Jun 15th 2013, 07:27 AMminneola24Re: Converting to polar (easy)
I'm confused why your adding pie,

And the book has 5,2.21. And -5, 5.356. As answers - Jun 15th 2013, 07:53 AMPlatoRe: Converting to polar (easy)
Have a look at this webpage. You will see the reply is correct.

The point $\displaystyle (-3,5)\in II$ and $\displaystyle {\frac{-\pi}{2}<\arctan \left( {\frac{{ - 4}}{3}} \right)}<0$ therefore adding $\displaystyle \pi$ gives the correct second quadrant angle.