Answer:
The required trigonometric form is [tex]4(\cos(60)-i\sin(60))[/tex]
Step-by-step explanation:
Given : Complex number [tex]-2+2\sqrt{3}i[/tex]
To find : Express the complex number in trigonometric form?
Solution :
The complex number [tex]a+ib[/tex] trigonometric form is [tex]r(\cos\theta+i\sin\theta)[/tex]
Where, [tex]r=\sqrt{a^2+b^2}[/tex]
and [tex]\theta=\tan^{-1}(\frac{b}{a})[/tex]
On comparing with given complex number [tex]-2+2\sqrt{3}i[/tex]
a=-2 and [tex]b=2\sqrt{3}[/tex]
Substitute the value,
[tex]r=\sqrt{a^2+b^2}[/tex]
[tex]r=\sqrt{(-2)^2+(2\sqrt{3})^2}[/tex]
[tex]r=\sqrt{4+12}[/tex]
[tex]r=\sqrt{16}[/tex]
[tex]r=4[/tex]
[tex]\theta=\tan^{-1}(\frac{b}{a})[/tex]
[tex]\theta=\tan^{-1}(\frac{2\sqrt3}{-2})[/tex]
[tex]\theta=\tan^{-1}(-sqrt3)[/tex]
[tex]\theta=\tan^{-1}(\tan(-60))[/tex]
[tex]\theta=-60[/tex]
Substituting all values in the formula,
[tex]r(\cos\theta+i\sin\theta)[/tex]
[tex]4(\cos(-60)+i\sin(-60))[/tex]
[tex]4(\cos(60)-i\sin(60))[/tex]
Therefore, The required trigonometric form is [tex]4(\cos(60)-i\sin(60))[/tex]
