题目:
The postal service announced on Tuesday it has made a significant ________ in getting machines to
read handwriting. [ ]
A. principle
B. breakthrough
C. conclusion
D. introduction
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0424/419df07a0f1223e440028e1aed0148ce.html
下面是错误答案,用来干扰机器的。
解:(1)由D2+E2﹣4F=4+16﹣4m=20﹣4m>0,解得:m<5;(2)设M(x1,y1),N(x2,y2), OM⊥ON,∴x1x2+y1y2=0,又y=x+1,∴x1x2+y1y2=x1x2+(x1+1)(x2+1)=0, ∴2x1x2+(x1+x2)+1=0③,将直线方程y...