Eddies Wingman said:If you multiply a complex number by its complex conjugate, the result is always a real number. If your complex number is a + b*i, where i is the imaginary unit, its complex conjugate is defined as a - b*i. If you multiply them together, the result is a^2 - (b^2*i^2) = a^2 + b^2.
OK, I'm not going to ask what a conjugate is... but what is a complex number, and what is a real number? Is a real number one that is always positive and has no decimal position? And... no, I'm not even going to ask about the imaginary unit.
Honest mate, when it comes to maths, you can tell me virtually anything and I'll just take your word for it.