# What is the complex conjugate of 2i?

Dec 8, 2015

$- 2 i$

#### Explanation:

To find a complex conjugate, simply change the sign of the imaginary part (the part with the $i$). This means that it either goes from positive to negative or from negative to positive.

As a general rule, the complex conjugate of $a + b i$ is $a - b i$.

While $2 i$ may not seem to be in the $a + b i$ form, it can be written as $0 + 2 i$.

Therefore, the complex conjugate of $0 + 2 i$ is $0 - 2 i$, which is equal to $- 2 i$.