What is the complex conjugate of 7i?

Oct 21, 2015

The complex conjugate of $7 i$ is $- 7 i$
The complex conjugate of a number $z$ is a number with opposite imaginary part.
So if $z = a + b i$ then conjugate is: $\overline{z} = a - b i$ for any $a , b \in \mathbb{R}$
We can note, that if we represent all complex numbers in coordinate system, then for any number: the number $z$ and its conjugate $\overline{z}$ are symetrical according to "real part" axis.