x/(x+1)<=ln(x+1)<=x

令f(x)=x/x+1,g(x)=ln(x+1),h(x)=x;

则f(x)<g(x)<h(x)

证明f(0)=g(0)=h(0)

而f'(x)<g'(x)<h'(x)

猜你喜欢

转载自www.cnblogs.com/dancer16/p/9465191.html
x
x1