How do you multiply # (-2-9i)(-3-6i) # in trigonometric form?
1 Answer
Feb 13, 2016
-48 +39i
Explanation:
distribute the brackets using FOIL
(-2 -9i )(-3 - 6i)
# = 6 + 12i + 27i + 54i^2 # [Note :
# i^2 = (sqrt-1)^2 = -1 # ]hence
# 6+ 12i + 27i + 54i^2 = 6 + 39i - 54 = - 48 + 39i #
