Elle G.

# Trig Question: What is the polar representation of z = 6i?

What is the polar representation of z = 6i?

a. 6cis i
b. 6 cis π
c. π cis 6
d. 6cis (π/2)
e. 36

I cant seem to figure this one out

By:

Tutor
4.8 (62)

I unveil the mysteries and secrets of trigonometry & you'll love it.

Elle G.

Thank you Kenneth! I'm not sure I'll ever really understand polar coordinates and representation but this helps a lot.
Report

06/02/17

Arturo O.

Elle,

In general, when given a complex number

z = x + iy,

the polar form is

z = re

where

r = √(x2 + y2)  [always positive]
φ = tan-1(y/x)  [Be careful with your selection of the quadrant for φ!]

But if x = 0 (as in your posted problem), then

z = yeiπ/2

This is true because the polar representation of i is

i = eiπ/2 = cos(π/2) + i sin(π/2) = 0 + i(1) = i
Report

06/02/17

## Still looking for help? Get the right answer, fast.

Get a free answer to a quick problem.
Most questions answered within 4 hours.

#### OR

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.