PDA

View Full Version : A problem in polar i want check my answer


r-soy
Apr19-10, 10:54 AM
write in polar form ...elc
-3 - 5i

my answer :

x = -3 y = - 5

r = root (-3)^2 + (-5)^2
= 5.83

tan Q = 5/3 = -1.12
tan-1 -1.12 = -0.84
Q = -0.84
Q = -pi + -0.84 = -3.981

Polar form = 5.83e^(-3.981)i

ammontgo
Apr19-10, 11:25 AM
Ok first off:
I believe you've recorded your answer in exponential form.

Forms of Complex Numbers:

https://dl.dropbox.com/u/4645835/MATH/ComplexForms.gif

Please correct me if I'm wrong.

ammontgo
Apr19-10, 11:34 AM
I think your angle may be wrong as well. This is what I did:

https://dl.dropbox.com/u/4645835/MATH/Ex1.gif

I can explain why I added 180 degrees to the angle I calculated - if needed.

r-soy
Apr19-10, 02:18 PM
Hi

but as I know in this question we change calculator to ( Rad ) nor (deg) because we have integer number -3 and - 5 not roots or ,

and please I want explaine more because I don't understand clearly

Mark44
Apr19-10, 02:28 PM
write in polar form ...elc
-3 - 5i

my answer :

x = -3 y = - 5

r = root (-3)^2 + (-5)^2
= 5.83

tan Q = 5/3 = -1.12
tan Q = 5/3, but 5/3 is not equal to -1.12

tan-1 -1.12 = -0.84
Q = -0.84
Q = -pi + -0.84 = -3.981

Polar form = 5.83e^(-3.981)i