# How do you add #(8-8i)+(-7-i)# in trigonometric form?

##### 1 Answer

Feb 15, 2017

#### Explanation:

Add them in rectangular form

- Combine the like terms:
#(8 + -7) + (-8i + -i) = 1-9i# #r = sqrt (1^2 + (-9)^2) = sqrt (82)# #theta = arctan(b/a) = arctan (-9/1) = arctan(-9)# #z = r(cos theta + i sin theta)#

#= sqrt(82)(cos(arctan(-9)) + i sin ((arctan (-9)))#