> 数学 >
证明:当x >0时,arctan x+1/x>π/2
人气:377 ℃ 时间:2020-06-11 03:56:21
解答
f'(x)=1/(1+x^2)-1/x^2=-1/(1+x^2)x^2<0
f(x)在x>0上单调递减
lim(x趋近于正无穷)f(x)=π/2+0=π/2
∴arctan x+1/x>π/2
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版