Question

几道求导数的题.1：(1/x)’ 2.（√2*x+1)’ 3.(t^2+1/t)’ 4.d(e^u*u) 5.(√x /

Answer 1

1：(1/x)’ =-1/x^2

2.（√2*x+1)’ =√2

3.(t^2+1/t)’ =2t-1/t^2

4.d(e^u*u) =ue^u+e^u=(u+1)e^u

5.(√x /（x^2+1）)’

=[1/2√x *(x^2+1)-2x√x ]/(x^2+1)^2

=[x^2+1-4x^2]/[2√x (x^2+1)^2]

=[1-3x^2]/[2√x (x^2+1)^2]