How do you differentiate y=x^2lnxy=x2lnx?

1 Answer
Nov 22, 2016

d/dx(x^2lnx)=x + 2xlnx ddx(x2lnx)=x+2xlnx

Explanation:

If you are studying maths, then you should learn the Product Rule for Differentiation, and practice how to use it:

d/dx(uv)=u(dv)/dx+(du)/dxv ddx(uv)=udvdx+dudxv, or, (uv)' = (du)v + u(dv)

I was taught to remember the rule in words; "The first times the derivative of the second plus the derivative of the first times the second ".

This can be extended to three products:

d/dx(uvw)=uv(dw)/dx+u(dv)/dxw + (du)/dxvw

So with f(x) = x^2lnx we have;

{ ("Let "u = x^2, => , (du)/dx = 2x'), ("And "v = lnx, =>, (dv)/dx = 1/x' ) :}

d/dx(uv)=u(dv)/dx + (du)/dxv
d/dx(x^2lnx)=(x^2)(1/x) + (2x)(lnx)
d/dx(x^2lnx)=x + 2xlnx