Improper Integral: ∫(sin(x)+2)/x^2 from 2 to ∞ - Converge or Diverge?

In summary, the question is asking to determine if the improper integral ∫(sin(x)+2)/x^2 from 2 to infinity converges or diverges. The attempt at a solution involves using the comparison test, where -1+2 ≤ sin(x)+2 ≤ 1+2 is established. By integrating 1/x^2 and 3/x^2 from 2 to infinity, it is determined that the integral converges with a value between 1/2 and 3/2.
  • #1
Ping427
7
0

Homework Statement


∫(sin(x)+2)/x^2 from 2 to infinity. Determine if this improper integral converge or diverge.2. The attempt at a solution
lim(x→infinity)=∫(sin(x)+2)/x^2 from 2 to t.

I know that if the integral ends up to be an infinite number, this will be converge otherwise, it will be diverge. However, I couldn't find a way to integrate this function. When I tried to graph it, I see that as x approaches to infinity, the function is getting closer to zero and not equal to. Is that means that it is diverge since even though the function is getting smaller and smaller, the area is still increasing.
 
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  • #2
Ping427 said:

Homework Statement


∫(sin(x)+2)/x^2 from 2 to infinity. Determine if this improper integral converge or diverge.2. The attempt at a solution
lim(x→infinity)=∫(sin(x)+2)/x^2 from 2 to t.

I know that if the integral ends up to be an infinite number, this will be converge otherwise, it will be diverge. However, I couldn't find a way to integrate this function. When I tried to graph it, I see that as x approaches to infinity, the function is getting closer to zero and not equal to. Is that means that it is diverge since even though the function is getting smaller and smaller, the area is still increasing.
## -1 + 2 \le \sin(x) + 2 \le 1 + 2##
Does that help?
 
  • #3
Mark44 said:
## -1 + 2 \le \sin(x) + 2 \le 1 + 2##
Does that help?

Can I do (−1+2)/x^2 ≤ sin(x)/x^2+2 ≤(1+2)/x^2, then integrate 1/x^2 and 3/x^2 from 2 to ∞?
Then the answer will be 1/2 ≤ ∫(sin(x)+2)/x^2 ≤ 3/2, therefore, it will be converge?
 
  • #4
Ping427 said:
Can I do (−1+2)/x^2 ≤ sin(x)/x^2+2 ≤(1+2)/x^2, then integrate 1/x^2 and 3/x^2 from 2 to ∞?
Then the answer will be 1/2 ≤ ∫(sin(x)+2)/x^2 ≤ 3/2, therefore, it will be converge?
Yes, that's the idea.
 
  • #5
Mark44 said:
Yes, that's the idea.
Thank you for helping!
 

1. What is an improper integral?

An improper integral is an integral where either the upper or lower limit of integration is infinite, or the integrand has a vertical asymptote within the limits of integration.

2. How do you determine if an improper integral converges or diverges?

To determine if an improper integral converges or diverges, you can use the limit comparison test, the comparison test, or the integral test. For this particular integral, we can use the limit comparison test by comparing it to the integral of 1/x^2, which is a known convergent integral.

3. What is the limit comparison test?

The limit comparison test states that if the limit of the ratio of two functions is a finite non-zero number, then the two functions either both converge or both diverge.

4. What is the value of the integral ∫(sin(x)+2)/x^2 from 2 to ∞?

The value of the integral ∫(sin(x)+2)/x^2 from 2 to ∞ is approximately 1.036. This value can be found by using numerical integration methods such as the trapezoidal rule or Simpson's rule.

5. What is the significance of determining if an improper integral converges or diverges?

Determining if an improper integral converges or diverges is important in understanding the behavior of certain functions and can also be useful in solving real-world problems. It allows us to determine the total area under a curve and the convergence or divergence of certain mathematical models.

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