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

Ping427
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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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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?
 
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?
 
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.
 
Mark44 said:
Yes, that's the idea.
Thank you for helping!
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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