Derivative of x ln x

ddx[xln⁡(x)]=ln⁡(x)+1\frac{d}{dx}\left[x \ln\left(x\right)\right] = \ln\left(x\right) + 1

A standard product-rule exercise: (x)′·ln x + x·(ln x)′ = ln x + 1. The minimum of x ln x sits where ln x = −1, at x = 1/e.

Derivation

  1. Logarithm rule

    ddx[ln⁡(x)]=1x\frac{d}{dx}\left[\ln\left(x\right)\right] = \frac{1}{x}
  2. Product rule

    With u = xx and v = ln⁡(x)\ln\left(x\right): (uv)′ = u′v + uv′.

    ddx[xln⁡(x)]=(1)(ln⁡(x))+(x)(1x)\frac{d}{dx}\left[x \ln\left(x\right)\right] = \left(1\right)\left(\ln\left(x\right)\right) + \left(x\right)\left(\frac{1}{x}\right)
0.511.522.53123
  • f(x) = x ln x
  • f′(x)

Drag the graph · at x = 1.96 the slope is 1.6729, the height of the dashed curve.

Open in the derivative calculator

Questions students ask

What is the derivative of x ln x?

ddx[xln⁡(x)]=ln⁡(x)+1\frac{d}{dx}\left[x \ln\left(x\right)\right] = \ln\left(x\right) + 1.

How do you find the derivative of x ln x?

A standard product-rule exercise: (x)′·ln x + x·(ln x)′ = ln x + 1. The minimum of x ln x sits where ln x = −1, at x = 1/e.

What is the integral of x ln x?

See the integral of x ln x page for the antiderivative with steps.