一道解一元二次不等式的题目.2x²-7x+6=2(x²-3.5x)+6=2(x²-3.5x+3.06_数学解答

一道解一元二次不等式的题目.
2x²-7x+6
=2(x²-3.5x)+6
=2(x²-3.5x+3.0625-3.0625)+6
=2(x²-3.5x+3.0625)-6.125+6
=2(x-1.75)²-0.125

人气：468 ℃　时间：2020-05-21 07:09:40

解答

(x-1.75)²<0.0625,那么开平方后得：+/-(x-1.75)<0.25,也就是x-1.75<0.25；或-(x-1.75)<0.25,即 x-1.75>-0.25.