Posted by **Amy** on Thursday, June 2, 2011 at 5:28am.

Given any Cartesian coordinates, (x,y), there are polar coordinates (r,theta) with –pi/2< theta < pi/2.

Find polar coordinates with –pi/2 < theta < pi/2 for the following Cartesian coordinate:

If (x,y) = (11,–7) then (r, theta)=( ____, _____ )

I was able to find r using r^2=x^2 + y^2, but I can't find theta. I found r to be 170^(1/2). I then tried using x= r*cos(theta), plugged in x=11 and r= 170^(1/2) and got theta = inverse cos (11/170^(1/2)), but that's not the correct answer. However my answer for r is correct. Any help would be very much appreciated, and thank you in advance! a detailed explanation would be nice since I still have several problems similar to this one to do :)

- Math (Calculus) -
**Amy**, Thursday, June 2, 2011 at 6:17am
nvm i got it

## Answer This Question

## Related Questions

- Calculus (polar coordinates) - Use polar coordinates to set up the double ...
- Maths - Polar Coordinate Systems - I've recieved an assignment to investigate ...
- calculus - for what value of r=4sinč have vertical tangent? In polar coordinates...
- Calculus - I wanted to confirm that I solved these problems correctly (we had to...
- Math (Trig) - Convert the Cartesian coordinate (-1,2) to polar coordinates, 0&#...
- Pre-calculus; urgent ! Please help ! - 1.Graph the polar equation r=3-2sin(theta...
- Precal - How do you find range of theta values for a polar equation? Usually the...
- Math (Polar to Cartesian Equations) - Convert the given polar equation to a ...
- Calculus please help ! - 1.Graph the polar equation r=3-2sin(theta) 2. Find the ...
- Math ! Please Help ! - 1.Graph the polar equation r=3-2sin(theta) 2. Find the ...

More Related Questions