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Grade 12Integral Calculus

how do i integrate this.. please help me out.. integrate e^(1+1/x)(x+1-1/x)

Profile image of Amritha
9 Years agoGrade 12
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1 Answer

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ApprovedApproved Tutor Answer1 Year ago

To integrate the expression \( e^{(1 + \frac{1}{x})}(x + 1 - \frac{1}{x}) \), we can break it down into manageable steps. The key is to recognize how the components of the expression relate to each other and how we can simplify the integration process.

Step-by-Step Integration Process

Let's start by rewriting the integral for clarity:

We want to compute:

\[ \int e^{(1 + \frac{1}{x})}(x + 1 - \frac{1}{x}) \, dx \]

Identifying Substitutions

Notice that the exponent \( 1 + \frac{1}{x} \) suggests a substitution might simplify our work. Let's set:

\[ u = 1 + \frac{1}{x} \]

Then, we differentiate \( u \) with respect to \( x \):

\[ \frac{du}{dx} = -\frac{1}{x^2} \]

This implies:

\[ du = -\frac{1}{x^2} \, dx \quad \Rightarrow \quad dx = -x^2 \, du \]

Expressing \( x \) in Terms of \( u \)

From our substitution, we can express \( x \) in terms of \( u \):

\[ \frac{1}{x} = u - 1 \quad \Rightarrow \quad x = \frac{1}{u - 1} \]

Now, substituting \( x \) back into the expression \( x + 1 - \frac{1}{x} \):

\[ x + 1 - \frac{1}{x} = \frac{1}{u - 1} + 1 - (u - 1) \]

After simplifying, we find:

\[ x + 1 - \frac{1}{x} = \frac{1 + (u - 1)(u - 1)}{u - 1} = \frac{u^2 - 1}{u - 1} \]

Rewriting the Integral

Now, substituting everything back into the integral, we have:

\[ \int e^u \left( \frac{u^2 - 1}{u - 1} \right) \left( -\frac{1}{(u - 1)^2} \right) du \]

This simplifies to:

\[ -\int e^u \frac{u^2 - 1}{(u - 1)^3} \, du \]

Final Steps

At this point, we can integrate \( e^u \) multiplied by a rational function. This may require integration by parts or further substitutions depending on the complexity of the resulting expression. However, the integral can be approached using standard techniques or numerical methods if necessary.

After integrating, don’t forget to substitute back \( u = 1 + \frac{1}{x} \) to express your final answer in terms of \( x \).

Summary

In summary, the integration of \( e^{(1 + \frac{1}{x})}(x + 1 - \frac{1}{x}) \) involves a strategic substitution that simplifies the expression significantly. By carefully manipulating the components and applying integration techniques, you can arrive at the solution. If you have any specific parts of the integration process that you find challenging, feel free to ask for further clarification!