Express the following complex numbers in the form
1 + i tan α
Given Complex number is Z=1+itanα
We know that the polar form of a complex number Z=x+iy is given by Z=|Z|(cosθ+isinθ)
Where,
|Z|=modulus of complex number=
θ =arg(z)=argument of complex number=
We know that tanα is a periodic function with period .
We have lying in the interval
Case1:
⇒
⇒
⇒
⇒
Since sec is positive in the interval
⇒
⇒
⇒
Since tan is positive in the interval
⇒ θ=
∴ The polar form is z=sec(cos
+isin
).
Case2:
⇒
⇒
⇒
⇒
Since sec is negative in the interval
.
⇒
⇒
⇒
Since tan is negative in the interval
.
⇒ .(∵ θ lies in 4th quadrant)
⇒ z=-sec(cos(
)+isin(
))
⇒ z=-sec(-cos
-isin
)
⇒ z=sec(cos
+isin
)
∴ The polar form is z=sec(cos
+isin
)