Question

Express in trigonometric form. -5i

Answer 1

a+ib=-5i
on comparing
a=0 and b=5

Answer 2

trigo form
=r*(cos(theta)+i*sin(theta))

Answer 3

where
\[r=\sqrt{a^{2}+b^{2}}\]

Answer 4

\[\theta=\tan^{-1} (\frac{ b}{ a })=\tan^{-1} \frac{ 5 }{ 0 }=\tan^{-1} \infty=\frac{ \pi }{ 2}\]

Answer 5

ab b is negative so
actual theta =pi-theta=pi/2

Answer 6

a+ib=r*(cos(theta)+i*sin(theta))
a=r*cos(theta)
b=r*sin(theta)