Question 240240
If you mean a quadratic equation, the formula is:


x = {{{(-b +- sqrt(b^2-4ac))/(2a)}}}


standard form of the quadratic equation is:


{{{ax^2 + bx + c = 0}}} where:


a is the coefficient of the {{{x^2}}} term.


b is the coefficient of the x term.


c is the constant.


You solve for x.


The y value is 0 because you set the equation equal to 0.


Your roots are:


(x,y) = (x,0) where you replace x with the values you calculated for x.


The roots can be real or imaginary.


If the roots are real, the graph of the equation crosses the x-axis at y = 0.


If the roots are not real (contain  an imaginary part which is a negative square root) then the graph of the equation will not cross the x-axis.


The quadratic formula works on all quadratic equations whether the roots are real or imaginary.