completing the square

the process of changing a polynomial of the form  into a perfect square trinomial , or

discriminant

the expression b2 – 4ac under the radical in the quadratic formula; the expression can be used to determine the number of real roots the quadratic equation has

quadratic formula

the formula  ; it is used to solve a quadratic equation of the form

roots of a quadratic equation

the x-intercepts of the parabola or the solution of the equation

x-intercept

the point where a line meets or crosses the x-axis