How do you add (2-8i)+(-2+4i)(28i)+(2+4i) in trigonometric form?

1 Answer
Dec 23, 2015

(2-8i)+(-2+4i)= 4(cos((3pi)/2)+isin((3pi)/2))(28i)+(2+4i)=4(cos(3π2)+isin(3π2))

Explanation:

I will assume that we are allowed to do the addition in rectangular form and then convert the answer into trigonometric form.

{: (,,"(",2,-8i,")"), ("+",,"(",-2,+4i,")"), (,,,"-------","-------",), ("=",,"(",0,-4i,")") :}

The general trigonometric form is
color(white)("XXX")abs(z)(cos(theta)+isin(theta))
where
color(white)("XXX")abs(z) is the distance from the origin (in the complex plane)
and
color(white)("XXX")theta# is the angle of the point (relative to the positive Real axis in the complex plane)
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