How do you multiply # (1-i)(-4-i) # in trigonometric form?
1 Answer
Sep 30, 2016
You distribute it like any two factors.
#color(blue)((1-i)(-4-i))#
#= (1*-4)+(1*-i)+(-i*-4)+(-i*-i)#
#= -4 - i + 4i + i^2#
#= -4 + 3i - 1#
#= color(blue)(-5 + 3i)#
