I have a simple problem with roots and absolute values. When is the root of a number both negative and positive? Is only the equation of a number say f(x) = √x both the negative root and the positive root?
If a = 1; b = -2, och x = a2√(ab-b2+2)
Why is x only 2 and not -2 aswell?
However if it were a function say f(x) the answer would be 2 and -2 right?
Edit: For clarification how come √4 = 2 but f(4) = √4 = 2 and -2