Rectangular to Polar (Quick)

[toxic grail]

tantheta is undefined, how do I proceed?

Trying to know which angle to give for -9 and 9.

[quiet wadi]

1. Ask your question and show the work you've done so far. If you've posted a screenshot of a question, specify which part you need help with.
2. Wait patiently for a helper to come along.
3. Once someone helps you, say thank you and close the thread with:

   +close
   

4. Feel free to nominate the person for helper of the week in #helper-nominations
5. Do not ping the mods, unless someone is breaking the rules. If there is a conflict amongst multiple helpers feel free to ping “Helper Mod”
6. If you're happy with the help you got here, and the server overall, you can contribute financially as well:

[severe elbow]

when tan(theta) is undefined, we know that cos(theta) equals zero

[toxic grail]

90 degrees

[severe elbow]

or 270

[toxic grail]

right

[severe elbow]

but since y is negative

we can eliminate 90

and we get 270

[toxic grail]

ok im following

so I give pi/2 for +9 and 3pi/2 for -9

but thats not the case

in the iamge

yo?

@severe elbow

[severe elbow]

the negative radius is for pi/2

because a negative radius reflects

[toxic grail]

can u elaborate this?