Skip to main contentSkip to solution

∫(1log⁡ex−1(log⁡ex)2)dx\int \left(\frac{1}{\log_e x} - \frac{1}{(\log_e x)^2}\right)dx is equal to

Solution

✅ Correct Option: 1

The integral to evaluate is ∫(1log⁡ex−1(log⁡ex)2)dx\int \left(\frac{1}{\log_e x} - \frac{1}{(\log_e x)^2}\right)dx.

Since the integrand contains log⁡ex\log_e x terms in the denominator, consider whether xlog⁡ex\frac{x}{\log_e x} could be the antiderivative.


Taking the derivative of y=xlog⁡exy = \frac{x}{\log_e x} using the quotient rule where u=xu = x and v=log⁡exv = \log_e x:

dudx=1\frac{du}{dx} = 1

dvdx=1x\frac{dv}{dx} = \frac{1}{x}

dydx=log⁡ex⋅(1)−x⋅1x(log⁡ex)2\frac{dy}{dx} = \frac{\log_e x \cdot (1) - x \cdot \frac{1}{x}}{(\log_e x)^2}

dydx=log⁡ex−1(log⁡ex)2\frac{dy}{dx} = \frac{\log_e x - 1}{(\log_e x)^2}


Splitting the fraction:

dydx=log⁡ex(log⁡ex)2−1(log⁡ex)2\frac{dy}{dx} = \frac{\log_e x}{(\log_e x)^2} - \frac{1}{(\log_e x)^2}

dydx=1log⁡ex−1(log⁡ex)2\frac{dy}{dx} = \frac{1}{\log_e x} - \frac{1}{(\log_e x)^2}

This matches the integrand exactly.


Therefore:

∫(1log⁡ex−1(log⁡ex)2)dx=xlog⁡ex+c\int \left(\frac{1}{\log_e x} - \frac{1}{(\log_e x)^2}\right)dx = \frac{x}{\log_e x} + c

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question