Let #v=-3i# and #w=2-4i#. What is #v*w#?

1 Answer
Jul 4, 2017

#v\cdotw=-6i-12#

Explanation:

#\color(indianred)(v=-3i)#
#\color(steelblue)(w=2-4i)#

#\thereforev\cdotw=\color(indianred)(-3i)\cdot(\color(steelblue)(2-4i))#
#=-3i(2)+(-3i)(-4i)=(-3xx2)(i)+(-3xx(-4))(ixxi)#
#-6i+12(-1)=-6i-12#