>>56
y=(x+1)/(x^2+5)
y'=(x+1)'(x^2+5)-(x+1)(x^2+5)'/(x^2+5)^2

y=√(3x^2+1)=(3x^2+1)^(1/2)
y'=(1/2)(3x^2+1)'(3x^2+1)^{(1/2)-1}