What is complex conjugate of #4-2i#?

1 Answer
Gió
Dec 3, 2015

#4+2i#

Explanation:

As you can see, the complex conjugate, #(4+2i)#, of your number is almost the same but with an opposite sign in the immaginary part.

An interesting property of complex conjugates is that if you multiply them together you get a pure real number!

So:

#(4-2i)(4+2i)=16cancel(+8i)cancel(-8i)-4i^2=16-4i^2=#
but #i^2=-1#
#=16color(red)(+)4=20# a pure real number!

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