Calculus - differentiation?

Question

Could you differentiate these equations and explain your answer? Thanks!

1. ln(cosx)/x^2

2.ln(√(x^2+1))

Answer 1

These are compositions...

1.- {1/Cos(x)*-Sin(x)*x^2 - [ln(cos(x))*2x]}/x^4

it is a quotient... So you differentiate using that rule....

2.- 1/Sqrt(x^2+1)*1/2Sqrt(x^2+1)*2x