find derivative of

f(x)=(sq.rt.)[x] - arctan(sq.rt.)[x]

my book says ((sq.rt.)(x))/(2(1+x)

however, online i found it to be (1/(2(sq.rt.)[x])) - (1/(2(sq.rt.)[x](x-1)))

i tried to simplify either one into the other, but no luck, so that means one of them is wrong...however, i cant find the derivative initially, so it doesnt matter

i would appreciate it if anybody could help me solve this