How do you divide (7-4i)/(3+2i) 74i3+2i in trigonometric form?

1 Answer
Mar 2, 2016

sqrt5xxe^(i(alpha-beta)5×ei(αβ), where alpha=tan^-1(-4/7)α=tan1(47) and beta=tan^-1(2/3)β=tan1(23)

Explanation:

(a+bi)(a+bi) an be written in as sqrt(a^2+b^2)e^(i(tan^-1(b/a))a2+b2ei(tan1(ba))

Hence, (7-4i)=sqrt(7^2+4^2)(e^(itan^-1(-4/7)))=sqrt65e^(itan^-1(-4/7))(74i)=72+42(eitan1(47))=65eitan1(47)

Similarly, (3+2i)=sqrt(3^2+2^2)(e^(itan^-1(2/3)))=sqrt13e^(itan^-1(2/3))(3+2i)=32+22(eitan1(23))=13eitan1(23)

Hence (7-4i)/(3+2i)=(sqrt65e^(itan^-1(-4/7)))/(sqrt13e^(itan^-1(2/3)))74i3+2i=65eitan1(47)13eitan1(23)

or sqrt5xxe^(i(tan^-1(-4/7))-(tan^-1(2/3)))5×ei(tan1(47))(tan1(23)) or

sqrt5xxe^(i(alpha-beta)5×ei(αβ), where alpha=tan^-1(-4/7)α=tan1(47) and beta=tan^-1(2/3)β=tan1(23)