Type your answer in the form a + bi
4/(5+i)
Are you familiar with the conjugate of a complex number? The conjugate of $\displaystyle a+bi$ is $\displaystyle a-bi$. Multiply top and bottom of your expression by the conjugate of the denominator. Multiplying any complex number by its conjugate will give a real number, so you are guaranteed to get a real number in the denominator.
Thanks Plato,
It was $\displaystyle {{\left| z \right|}^2} $ that threw me.
So if z=5+6i then $\displaystyle {{\left| z \right|}^2} $ = $\displaystyle {5^2+6^2} $
I assume that this is also standard notation? Or is there some logic to it that I am missing?
This is the first time I have tried to use Latex. I copied yours. I am just a little pleased with myself.
Thanks.