How do you multiply # (8-2i)(-3+7i) # in trigonometric form?
1 Answer
May 8, 2016
FOIL
Explanation:
If it was
You would foil, and you would do that same thing.
Now, lets foil with
-
First
#(8*-3)=-24# -
Outer
#(8*7i) = 56i# - Act
#i# like#x#
- Act
-
Inner
#(-2i*-3)=6i# -
Last
#(-2i*7i)=-14i^2=-14*-1=14# - Remember #i^2 = -1
Now put it all back together
Combine like terms
