一、少用蛮动多用巧动解题要求正确而简捷,而简捷多半要借助于认真观察、深入思考,不满足于检式套语,勇于创新.例1 已知方程2(m+1)x~2+4mx+3m-2=0的两根异号、试确定实数 m 的范围.分析此题常见的解题方案是由二次项系数不等于0、判别式大于0及两根之积小于0,所组成的不等式组给定.其实,两根异号,只要求两根之积小于0即可.这是因为对于 ax~2+bx+c=0(a≠0)而 One, less use of savage and more use of clever movement to solve the problem requires correct and simple, and most of the simple and quick to rely on careful observation, in-depth thinking, not satisfied with the type of test, innovation. Example 1 Known Equation 2 (m +1) x With two different signs of ~2+4mx+3m-2=0, try to determine the range of real numbers m. The common solution to this problem is the product of the quadratic term coefficient not equal to zero, the discriminant type greater than zero, and the product of two roots. Less than 0, the composition of the inequality group given. In fact, two different signs, only two products of less than 0 is required. This is because for ax ~ 2 + bx + c = 0 (a ≠ 0) and