How do you multiply # (5-12i)(2+3i) # in trigonometric form?

1 Answer
Mia
Nov 20, 2016

#=46-19i#

Explanation:

Expanding these factors is determined by applying Distributive property.
#" "#
#" "#
Distributive Property:
#" "#
#color(blue)((a+b)(c+d) = axxc + axxd + bxxc + bxxd)#
#" "#
#" "#
#(5 - 12i)(2 + 3i) #
#" "#
#=color(blue)(5xx2 + 5xx3i +(-12i)xx2 + (-12ixx3i))#
#" "#
#=10 + 5i -24i -36i^2#
#" "#
#=10 -19i-36xx-1" "#As we know #" "i^2=-1#
#" "#
#=10-19i+36#
#" "#
#=46-19i#

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