Integral of 1/x

∫1x dx=ln⁡(∣x∣)+C\int \frac{1}{x}\,dx = \ln\left(\left|x\right|\right) + C

The one power the power rule cannot handle (it would divide by zero). The antiderivative is ln|x|, and the absolute value makes it valid for negative x too.

Step by step

  1. Reciprocal rule

    ∫1/u du = ln|u|.

    ∫1x dx=ln⁡(∣x∣)\int \frac{1}{x}\,dx = \ln\left(\left|x\right|\right)
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  • f(x) = 1/x
  • F(x) + C

Every choice of C gives a valid antiderivative, since shifting up or down doesn’t change the slope.

Open in the integral calculator

Questions students ask

What is the integral of 1/x?

∫1x dx=ln⁡(∣x∣)+C\int \frac{1}{x}\,dx = \ln\left(\left|x\right|\right) + C.

How do you integrate 1/x?

The one power the power rule cannot handle (it would divide by zero). The antiderivative is ln|x|, and the absolute value makes it valid for negative x too.

How can I check the answer?

Differentiate it: the derivative of ln⁡(∣x∣)\ln\left(\left|x\right|\right) is 1x\frac{1}{x}. CalcViz checks every antiderivative this way before showing it.