Integrating e^X - e^-x/e^-x+1 dx

In summary, the conversation revolves around integrating a specific expression involving e^x and e^-x. The expert suggests factoring out e^x from the numerator and using substitution to make the integral more manageable. The conversation ends with a question about the use of e^x in the differential instead of e^-x.
  • #1
markosheehan
136
0
how do you integrate e^X-e^-x/e^-x+1 dx
i am trying multiplying by e^x and trying to make it into no fraction but i am having no luck
 
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  • #2
markosheehan said:
how do you integrate e^X-e^-x/e^-x+1 dx
i am trying multiplying by e^x and trying to make it into no fraction but i am having no luck

do you mean integrate

$\dfrac{e^x - e^{-x}}{e^{-x}+1}$ or $e^x - \dfrac{e^{-x}}{e^{-x}+1}$
 
  • #3
The first one
 
  • #4
markosheehan said:
how do you integrate e^X-e^-x/e^-x+1 dx
i am trying multiplying by e^x and trying to make it into no fraction but i am having no luck
Instead of multiplying by e^x, I would factor an e^x out of the numerator:
$\int \frac{e^x- e^{-x}}{e^{-x}+ 1}dx= \frac{1- e^{-2x}}{e^{-x}+ 1} e^xdx$

Let $u= e^{-x}$ so $du= -e^{-x}dx$. The integral becomes $-\int\frac{1- u^2}{u+ 1}du$. I presume you know that $1- u^2= (1- u)(1+ u)$.
 
  • #5
HallsofIvy said:
Instead of multiplying by e^x, I would factor an e^x out of the numerator:
$\int \frac{e^x- e^{-x}}{e^{-x}+ 1}dx= \frac{1- e^{-2x}}{e^{-x}+ 1} e^xdx$

Let $u= e^{-x}$ so $du= -e^{-x}dx$. The integral becomes $-\int\frac{1- u^2}{u+ 1}du$. I presume you know that $1- u^2= (1- u)(1+ u)$.

Why would you factor out e^x to be used in your differential when you need e^(-x)?
 

FAQ: Integrating e^X - e^-x/e^-x+1 dx

What is the purpose of integrating e^x - e^-x/e^-x+1 dx?

The purpose of integrating e^x - e^-x/e^-x+1 dx is to determine the area under the curve of the given function. This area represents the total change in the function over a given interval.

How is the integral of e^x - e^-x/e^-x+1 dx calculated?

The integral of e^x - e^-x/e^-x+1 dx is calculated using the power rule and substitution method. First, we use substitution to rewrite the expression as (e^x - 1)/(e^x + 1). Then, we use the power rule to integrate the expression, resulting in ln|e^x + 1| + C.

What is the significance of the constant C in the solution of the integral?

The constant C in the solution of the integral represents the arbitrary constant of integration. It is added to account for all possible solutions and to make sure the integral is valid for all values of x.

Can the integral of e^x - e^-x/e^-x+1 dx be approximated?

Yes, the integral of e^x - e^-x/e^-x+1 dx can be approximated using numerical methods such as the trapezoidal rule or Simpson's rule. These methods divide the interval into smaller parts and use a formula to approximate the area under the curve.

What are the applications of integrating e^x - e^-x/e^-x+1 dx?

The integration of e^x - e^-x/e^-x+1 dx has various applications in mathematics and science. It is used in calculating the growth and decay of populations, in solving differential equations, and in finding the total distance traveled by an object with varying velocity. It is also used in physics and engineering to determine the work done by a variable force.

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