Medals Medals!
Compute the modulus and argument of each complex number..
1. -5i
2. sqrt10(cos(5pi/7)+isin(5pi/7)

Question

Medals Medals!
Compute the modulus and argument of each complex number..
1. -5i
2. sqrt10(cos(5pi/7)+isin(5pi/7)

hartnn · Answer

modulus is 'r'
argument is 'theta

hartnn · Answer

for 2nd,
compare your expression with 
$\large r(\cos \theta +i\sin \theta)$

hartnn · Answer

for 1st.

x+iy = 0-5i

x=0, y=-5
use the formulas to calculate r and theta

anonymous · Answer

okay, so its going to look like (0, -5) right? i worked of an example i saw and my modulus became 55.9 and was stated as being "undefined"

anonymous · Answer

sorry, it was 5 and not 55.9!!

anonymous · Answer

i dont know where that came from

hartnn · Answer

theta was stated as undefined ?

anonymous · Answer

yeah, but im not so sure

hartnn · Answer

where does 0,-5 point lie ?

anonymous · Answer

on the y ais

hartnn · Answer

not in any quadrant :P

anonymous · Answer

yeah, my bad!

hartnn · Answer

|dw:1406837518938:dw|
negative y axis