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

1 Answer
May 6, 2016

In trigonometric form : #0.632[cos(-71.565)+i sin(-71.565)]#

Explanation:

#(-4i+2)/(i+7) = ((-4i+2)(i-7))/((i+7)(i-7)) = (-4*i^2-14+30*i)/(i^2-7^2) =(-1/50)*(-10+30i)=0.2-0.6i#. Let #Z=0.2-0.6i# Modulas Z= #sqrt(0.2^2+(-0.6)^2) = .632# Argument Z #theta=tan^-1((-0.6)/(0.2))=tan^-1(-3)=-71.565^0# Hence Z expressed in trigonometric form: #0.632[cos(-71.565)+i sin(-71.565)]#[Ans]