looks like z1 is in QIV, since x>0 and y<0
so, θ = 360 - arctan(8/6) = 360 - 53.1 = 306.9°
z1 = 10 cis 306.9°
z2 = 5 cis 60°
z1*z2 = 10*5 cis (-53.1+60) = 50 cis 6.9°
z1^4 = 10^4 cis 4*(-53.1)
= 10000 cis -212.4°
= 10000 cis 147.6°
x = 10000 cos 147.6° = -8443
y = 10000 sin 147.6° = 5358
z1^4 = -8443 + 5359i
Suppose that z1=6-8i. Find:
A. The Trig Form of the complex number z1, where your theta is in degrees.
B. The Trig form of z1*z2, where
z2=5[cos(60degrees)+isin(60degrees)]
C. The Trig Form of (z1)^4
1 answer