How do you add (2+8i)+(3+4i) in trigonometric form?

1 Answer
May 18, 2016

(2+8i)+(3+4i)=sqrt68[cosalpha+isinalpha]+5[cosbeta+issinbeta],

where alpha=arctan4 and beta=arctan(4/3).

Explanation:

Let us first write (2+8i) and (3+4i) in trigonometric form.

a+ib can be written in trigonometric form rcosthetaa+irsintheta=r(costhetaa+isintheta),
where r=sqrt(a^2+b^2) and tantheta=b/a or theta=arctan(b/a)

Hence (2+8i)=sqrt(2^2+8^2)[cosalpha+isinalpha] or

sqrt68[cosalpha+isinalpha], where alpha=arctan4 and

(3+4i)=sqrt(3^2+4^2)[cosbeta+isinbeta] or

5[cosbeta+issinbeta], where beta=arctan(4/3)

Hence (2+8i)+(3+4i) =

sqrt68[cosalpha+isinalpha]+5[cosbeta+issinbeta],

where alpha=arctan4 and beta=arctan(4/3).