#### Answer

As real conjugates are symmetric across the imaginary y-axis, the Julia set must be symmetric with respect to the imaginary y-axis too.

#### Work Step by Step

For $z = a + bi$, real conjugate of $z$ is -a + bi.
Same like complex conjugates, real conjugates also have the same absolute values.
As real conjugates are symmetric across the imaginary y-axis, the Julia set must be symmetric with respect to the imaginary y-axis too.