Definition of the Complex Conjugate
The complex conjugate is found by taking the sign of the imaginary portion of a complex number and changing it to the opposite sign.
If there is a complex number,
$ a + bi $
where $ a $ and $ b $ are arbitrary constants, then the complex conjugate is
$ a - bi $.
Vice versa, if there is a complex number
$ a - bi $
then the complex conjugate is
$ a + bi $.