1. Problem statement: Find the complex conjugate of a complex number $A$. 2. Formula: The complex conjugate of a complex number $A = a + bi$ (where $a$ and $b$ are real numbers and $i$ is the imaginary unit) is given by: $$A^* = a - bi$$ 3. Explanation: The complex conjugate changes the sign of the imaginary part while keeping the real part the same. 4. Example: If $A = 3 + 4i$, then its complex conjugate is: $$A^* = 3 - 4i$$ 5. Summary: To find the complex conjugate, simply negate the imaginary part of the complex number.