Take 10 minutes to prepare this exercise.
Then, if you lack ideas to begin, look at the given clue and start searching for the solution.
A detailed solution is then proposed to you.
If you have more questions, feel to ask then on the forum.
Question
Prove that
their, assuming
prove that
Indice
Use the formula
to prove that
Remember also that
Solution
By taking as definition of the absolute value
we have:
Using the property of the conjugate of a product and the commutativity of the multiplication of complex numbers, we have:
It is a bit longer using the expression
