Question Number 86552 by M±th+et£s last updated on 29/Mar/20
![proe that f(x)=x+[x] increase in R](Q86552.png)
$${proe}\:{that} \\ $$$${f}\left({x}\right)={x}+\left[{x}\right]\: \\ $$$${increase}\:{in}\:{R} \\ $$
Commented by mathmax by abdo last updated on 29/Mar/20
![f^′ (x)=1 because [x] ∈Z ⇒f is increasing at R](Q86557.png)
$${f}^{'} \left({x}\right)=\mathrm{1}\:\:\:\:\:\:{because}\:\left[{x}\right]\:\in{Z}\:\Rightarrow{f}\:{is}\:{increasing}\:{at}\:{R} \\ $$
Commented by M±th+et£s last updated on 29/Mar/20
$${thank}\:{you}\:{sir} \\ $$
Commented by mathmax by abdo last updated on 30/Mar/20
$${you}\:{are}\:{welcome}. \\ $$