Efficient Integration of Step Function with Variable Denominator

In summary, the conversation revolved around calculating the integral of a step function and how to approach it. The participants discussed rewriting the function and breaking the integral into various segments based on the constant values of g(x). They also provided guidance on how to continue with the calculation.
  • #1
Rectifier
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The problem
I want to calculate ## \int^6_{-6} \frac{g(x)}{2+g(x)} \ dx ## for the step function below.
2YSK7nM.jpg
The attempt
I started with rewriting the function as with the help of long-division
## \int^6_{-6} \frac{g(x)}{2+g(x)} \ dx = \int^6_{-6} 1 \ dx - 2\int^6_{-6} \frac{1}{g(x)+2} \ dx##

I know that ##\int^6_{-6} 1 \ dx = 12## but that's about it. I am not sure how I should continue.

And here is where I get stuck.
 
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  • #2
If you look closely at ## g(x) ##, it takes on constant values for various intervals. You need to break up the integral from -6 to 6 into these various segments.
 
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  • #3
Rectifier said:
The problem
I want to calculate ## \int^6_{-6} \frac{g(x)}{2+g(x)} \ dx ## for the step function below.
2YSK7nM.jpg
The attempt
I started with rewriting the function as with the help of long-division
## \int^6_{-6} \frac{g(x)}{2+g(x)} \ dx = \int^6_{-6} 1 \ dx - 2\int^6_{-6} \frac{1}{g(x)+2} \ dx##

I know that ##\int^6_{-6} 1 \ dx = 12## but that's about it. I am not sure how I should continue.

And here is where I get stuck.
This shouldn't be too difficult. On the interval [-6, -4], g(x) = -1, so g(x) + 2 = 1. What is ##\int_{-6}^{-4} \frac 1 1 dx##? Do the same for the other intervals.
 
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  • #4
Hi Rectifier:

I suggest breaking the integral into six pieces, one piece for each step. For each piece, g(x) has a specific constant value, so the integrand is a specific constant.

Hope this helps.

Regards,
Buzz
 
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  • #5
Thank you for your help, everyone!
 
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Related to Efficient Integration of Step Function with Variable Denominator

What is a step function integral?

A step function integral is a mathematical concept used to calculate the area under a step function curve. A step function is a piecewise constant function, meaning it has a constant value within each interval, with sudden jumps between intervals. The step function integral is used to find the total change in the function over a given interval.

How is a step function integral calculated?

The step function integral is calculated by breaking the function into smaller intervals where it is constant, finding the area of each interval, and then adding all the areas together. This can be done using geometric shapes such as rectangles or trapezoids, or by using calculus methods such as the Riemann sum or the definite integral.

What is the purpose of a step function integral?

The purpose of a step function integral is to find the total change in a function over a given interval. This can be useful in many real-world applications, such as calculating the total distance traveled by an object with a changing velocity, or finding the total amount of a substance produced in a chemical reaction with varying rates.

What are some common applications of step function integrals?

Step function integrals are commonly used in economics, physics, engineering, and other fields that involve analyzing changing quantities over time or distance. They can be used to model population growth, stock market fluctuations, temperature changes, and many other phenomena.

What are the limitations of using a step function integral?

While step function integrals can be useful in many applications, they have some limitations. They are primarily used for functions that have sudden jumps or changes, so they may not be suitable for analyzing smooth, continuous functions. Additionally, they may not accurately represent the true behavior of a system if the intervals chosen are too large or small.

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