Quadratic Equation

Quadratic Equation Video   In algebra, a quadratic equation (from Latin quadratus 'square') is any equation that can be rearranged in standard form as[1]

{displaystyle ax^{2}+bx+c=0,,}

where x represents an unknown value, and ab, and c represent known numbers, where a ≠ 0. (If a = 0 and b ≠ 0 then the equation is linear, not quadratic.) The numbers ab, and c are the coefficients of the equation and may be distinguished by respectively calling them, the quadratic coefficient, the linear coefficient and the constant coefficient or free term.   The values of x that satisfy the equation are called solutions of the equation, and roots or zeros of the expression on its left-hand side. A quadratic equation has at most two solutions. If there is only one solution, one says that it is a double root. If all the coefficients are real numbers, there are either two real solutions, or a single real double root, or two complex solutions that are complex conjugates of each other. A quadratic equation always has two roots, if complex roots are included; and a double root is counted for two. A quadratic equation can be factored into an equivalent equation[3]

{displaystyle ax^{2}+bx+c=a(x-r)(x-s)=0}

where r and s are the solutions for x.