(4+4i)/(5+6i) ;Z=a+ib 4+4i5+6i;Z=a+ib. Modulus: |Z|=sqrt (a^2+b^2)|Z|=√a2+b2;
Argument:theta=tan^-1(b/a)θ=tan−1(ba) Trigonometrical form :
Z =|Z|(costheta+isintheta)Z=|Z|(cosθ+isinθ) Z_1= 4+4 i Z1=4+4i
Modulus:|Z_1|=sqrt(4^2+4^2)~~ 5.66 |Z1|=√42+42≈5.66
Argument: tan alpha= (|4|)/(|4|):. alpha = tan^-1 (1)=0.785
Z_1 lies on first quadrant, so theta =alpha ~~ 0.785
:. Z_1=5.66(cos 0.785+isin 0.785)
Z_2= 5 + 6i . Modulus:|Z|=sqrt(5^2+6^2)
=sqrt 61 ~~ 7.81 Argument: tan alpha= (|6|)/(|5|)
=6/5 :.alpha =tan^-1 (1.2) ~~ 0.0876 ; Z_2 lies on first
quadrant.:. theta=alpha ~~0.876
:. Z_2=7.81(cos 0.876+isin 0.876) :. (4+4i)/(5+6i) =
Z= (5.66(cos0.785+isin 0.785))/(7.81(cos 0.876+isin 0.876)
Z=0.725(cos(0.785-0.876)+isin (0.785-0.876)) or
Z=0.725(cos (-0.091)+isin (-0.091)) or
Z=0.725(cos (0.091)-isin (0.091))=(44/61-4/61 i )
In trigonometric form: 0.725(cos 0.091-isin 0.091) [Ans]