1.
Explicație pas cu pas:
f'(x)= (x'•(x+1)-x•(x+1)' )/(x+1)^2=(x+1-x)/(x+1)^2=1/(x+1)^2
f''(x)=( 1/(x+1)^2)'=-2(x+1)/(x+1)^4= -2/(x+1)^3
