题目

求证函数y=是奇函数,且在定义域上是增函数. 答案：思路分析:本题在证明过程中使用了三段论推理,假言推理等推理规则.解:y=所以f(x)的定义域为x∈R.f(-x)+f(x)=(1-)+(1-)=2-(+)=2-()=2-=2-2=0,即f(-x)=-f(x),所以f(x)是奇函数.任取x1,x2∈R,且x1＜x2.则f(x1)-f(x2)=(1-)-(1-)=2(-)=2·.由于x1＜x2,从而,所以f(x1)＜f(x2),故f(x)为增函数.—How come Tom picked a quarrel with his wife?—________? We also have the occasional argument.A.What's onB.How's thatC.Who doesn'tD.Why not