# How do you add (2-5i)+(7-i) in trigonometric form?

Mar 22, 2018

$9 - 6 i$

#### Explanation:

We define the addition of two complex numbers $a + b i$ and $c + \mathrm{di}$ as follows

$\left(a + b i\right) + \left(c + \mathrm{di}\right) : = \left(a + c\right) + \left(b + d\right) i$

So

$\left(2 - 5 i\right) + \left(7 - i\right) = \left(2 + 7\right) + \left(- 5 - 1\right) i = 9 - 6 i$