形如ax~2+bx+c=0(a≠0)的方程叫做一元二次方程.当b~2-4ac≥0时,一元二次方程ax~2+bx+c=0(a≠0)的两根为x_(1、2)=(-b±(b~2-4ac)~(1/2))/2a1.直接开平方法、配方法、公式法、因式分解法是一元二次方程的四种基本解法.2.公式法是解一元二次方程最一般的方法:(1)b~2-4ac<0时,方程ax~2+bx+c=0(a≠0)有两个不相等的实数根x_(1、2)=(-b±(b~2-4ac)~(1/2))/2a The equation of the form ax ~ 2 + bx + c = 0 (a ≠ 0) is called the univariate quadratic equation. When b ~ 2-4ac≥0, the quadratic equation ax ~ 2 + bx + c = 0 0) is x1 (1,2) = (- b ± (b ~ 2-4ac) ~ (1/2)) / 2a1. The direct Kaiping method, formula method, formula method, factorization method is a dollar The quadratic equation of the four basic solutions .2. Formula method is the most general solution to a quadratic equation: (1) b ~ 2-4ac <0, the equation ax ~ 2 + bx + c = 0 ) Has two unequal real roots x_ (1,2) = (- b ± (b ~ 2-4ac) ~ (1/2)) / 2a