idk if this is supposed to be common sense but, i need help understanding why when i make this equation solve for (y) that there is a plus/minus answer.
(yx)yx = 2x
y = .5(sqrt(2x)/2)
y = .5(-sqrt(2x)/2)
y^2 x^2 = 2x
y^2 = 2x/x^2
y^2 = 2/x , clearly x > 0, (something squared could not be negative)
y = ± √2/√x
y = ± √2/√x * √x/√x
= ± √(2x) / x
Whenever you have an equation of the form
x^2 = k, where k is a positive number
then x = ± √k
e.g. x^ = 9
then x = ± √9 = ± 3
notice that both +3 and -3 satisfy the original equation.