Question

Given the following point, (0,-18) , in rectangular coordinates. Find another point in polar coordinates with the following conditions

Conditions:
1. r > 0
0<= theta < 2pi

2. r<0
0<= theta < 2pi

3. r>0
-2pi <= theta <0

4. r<0
-2pi <= theta <0

Answer 1

Did you have any ideas on where to start with this problem?
I assume the problem wishes for us to convert (0, -18) into polar coordinates in these four ways.

Answer 2

someone is here to help, amazing and yea i think i almost have this figured out

Answer 3

from cart coords to polar coords i used r^2=x^2+y^2 and tantheta=y/x, xcannot = 0

Answer 4

so i know that r=18 and theta = DNE and the first condition is that r > 0
0<= theta < 2pi the polar coord should be (18,3pi/2)

Answer 5

That looks good to me.

Answer 6

so, up till the 4th condition i'm having a slight trouble.

Answer 7

i know the polar coord is double negative and r =-18

Answer 8

is it -pi-(3pi/2)=-pi/2 ?

Answer 9

oh, wait i think i figured it out, its -3pi/2

Answer 10

I'm thinking if you plotted (18, -pi/2) you'd have the right point but then switching to -18 would be opposite. Yeah.

Answer 11

the 4th condition is basically a reflection of the 3rd condition

Answer 12

alright ty for the help.

Answer 13

No problem! :p