Let `f(x)=x/(1+x^2) and g(x)=(e^(-x))/(1+[x])` (where [.] denote greatest integer function), then

Options

A. `f(x)` is monotonically decreasing in `[1,3.8]`
B. `f(x)` is monotonically increasing i `[1,3.8]`
C. the greatest value of `f(x)` is `1/3xx14.44`
D. the least value of `f(x)` is `2`

Answer

D

Explanation

`y={(x^(2)+1,1lexlt2),((x^(2)+1)/2,2lexlt3),((x^(2)+1)/3,3lexle3.8):}`
least value of `f(x)` is `2`