11-2

In chapter 11 section 2 it is dealing wit complex numbers.

Rectangular= -2=x+yi

Polar= -2=rcostheta+rsinthetai-> from 11-1
If u want to abbreviate to 2=rcis

To multiply complex numbers

Rectangular – foil

Polar – multiply r; add thetas


Express
2cis45degrees to rectangular

x=rcostheta=2cos45degrees=2(square root of 2/2)=square root of 2
y=rsintheta=2sin45degrees=2(square root of 2/2)=square root of 2

z=square root of 2+square root of 2 i


Express 2
Z=1-square root of 3 in polar
Square root of 1^2 +square root of 3^2=1+3= square root of 4 = +/-2

Tan –square root of 3/1=theta=tan^-1square root of 3

60 where it – second Q and 3rd .

Q2= 120degrees Q3= 300 degrees.

Z=2cis300degrees
Z=2cos300degrees+2sin300degreesi
Z=-2cis120degrees
Z=-2cos 120degrees+-2sin 120degreesi
All you answer above

Z1*Z2

Z1 2cis 30 z2 3 cis 20

= 6cis 50degrees

Basically section11-2 is weird long and aggravating. If you know what you are doing and know all your formulas it will be easy for you