The function $y=\tan x-x$ is

Question

(1)an increasing function in $( 0 ,\frac{\pi}{2})$(2)an decreasing function in $(0 ,\frac{\pi}{2})$(3)increasing  in $(0 ,\frac{\pi}{4})$decreasing  in $(\frac{\pi}{4} ,\frac{\pi}{2})$(4)decreasing  in $(0 ,\frac{\pi}{4})$ increasing in $(\frac{\pi}{4} ,\frac{\pi}{2}$)