How do you divide ( 4i+4) / (6i +5 )4i+46i+5 in trigonometric form?

1 Answer
Feb 27, 2018

In trigonometric form: 0.725(cos 0.091-isin 0.091)0.725(cos0.091isin0.091)

Explanation:

(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=tan1(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+425.66

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]