Home
Class 12
MATHS
Evaluate: inte^(e^2) (dx)/(x log x)...

Evaluate: `int_e^(e^2) (dx)/(x log x)`

Text Solution

AI Generated Solution

The correct Answer is:
To evaluate the integral \( I = \int_e^{e^2} \frac{dx}{x \log x} \), we will follow these steps: ### Step 1: Substitution Let \( t = \log x \). Then, differentiating both sides gives us: \[ \frac{dt}{dx} = \frac{1}{x} \implies dx = x \, dt \] Since \( x = e^t \), we can substitute \( dx \) as: \[ dx = e^t \, dt \] ### Step 2: Change the limits of integration When \( x = e \): \[ t = \log e = 1 \] When \( x = e^2 \): \[ t = \log e^2 = 2 \log e = 2 \] ### Step 3: Substitute in the integral Now substituting \( x \) and \( dx \) into the integral: \[ I = \int_{1}^{2} \frac{e^t \, dt}{e^t \cdot t} = \int_{1}^{2} \frac{dt}{t} \] ### Step 4: Evaluate the integral The integral \( \int \frac{dt}{t} \) is: \[ \int \frac{dt}{t} = \ln |t| \] Thus, we evaluate it from 1 to 2: \[ I = \left[ \ln t \right]_{1}^{2} = \ln 2 - \ln 1 \] ### Step 5: Simplify the result Since \( \ln 1 = 0 \): \[ I = \ln 2 - 0 = \ln 2 \] ### Final Answer Thus, the value of the integral is: \[ \boxed{\ln 2} \] ---
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • INTEGRALS

    MODERN PUBLICATION|Exercise EXERCISE 7.1|29 Videos
  • INTEGRALS

    MODERN PUBLICATION|Exercise EXERCISE 7.5|23 Videos
  • INTEGRALS

    MODERN PUBLICATION|Exercise TRUE/FALSE QUESTIONS|10 Videos
  • DIFFERENTIAL EQUATIONS

    MODERN PUBLICATION|Exercise CHAPTER TEST (9)|12 Videos
  • INVERSE - TRIGONOMETRIC FUNCTIONS

    MODERN PUBLICATION|Exercise CHAPTER TEST (2)|11 Videos

Similar Questions

Explore conceptually related problems

Evaluate :int_(e)^(e^(2)){(1)/(log x)-(1)/((log x)^(2))}dx

Evaluate int e^x/log(e^x)dx

Evaluate: int(e^(x))/(x){x(log x)^(2)+2log x}dx

Evaluate : int_0^(ln2)x e^(-x)dx

Evaluate int log_e(a^x)dx

int_(1)^(e^(2))(dx)/(x(1+log x)^(2))=

Evaluate int(log_(e)x)^(2)dx

int_(1//e)^(e) (dx)/(x(log x)^(1//3))

Evaluate int log_e(a^2+x^2)dx

Evaluate: int e^(x log a)+e^(a log x)+e^(a log a)dx