Convergence or Divergence of ∑ tan(1/k) for k=5

In summary, the conversation discusses the convergence or divergence of the series ∑tan(1/k) as k approaches infinity, and the use of various tests such as the ratio test and divergence test to determine its behavior. The suggestion to use the comparison test is also mentioned, along with a possible function to compare with. Finally, the result that \tan\left(\frac1k\right) \geq \frac{2}{\pi k} is brought up as a potential solution.
  • #1
cloveryeah
26
0

Homework Statement



∑ tan(1/k)
k=5

show that it is convergent or divergent

Homework Equations

The Attempt at a Solution


i used ratio test, but it's equal to 1, it means no works...
i used divergence test, it equals to 0, no work too...
so what should i do? i don't know how to use comparision test to attempt this problem
 
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  • #2
What is tan(0.001)? tan(0.0000001)? Do you see some function that looks similar and could be used for comparison?
 
  • #3
Use the result that if [itex]0 < x \leq \frac12\pi[/itex] then [itex]\sin x \geq \frac{2x}{\pi}[/itex] to show that [tex]
\tan\left(\frac1k\right) \geq \frac{2}{\pi k}.[/tex]
 

FAQ: Convergence or Divergence of ∑ tan(1/k) for k=5

What is convergence or divergence?

Convergence and divergence are terms used in mathematics and science to describe the behavior of a sequence or a series. A sequence is said to converge if its terms approach a specific value as the number of terms increases. A series is said to converge if the sum of its terms approaches a finite value as the number of terms increases. Conversely, a sequence or series is said to diverge if its terms do not approach a specific value or if its sum does not approach a finite value.

What are the types of convergence?

The two main types of convergence are pointwise convergence and uniform convergence. Pointwise convergence is when the terms of a sequence approach a specific value at each point in the domain. Uniform convergence is when the terms of a sequence approach a specific value at every point in the domain simultaneously.

How is convergence or divergence determined?

Convergence or divergence is determined by evaluating the limit of the terms of a sequence or series as the number of terms approaches infinity. If the limit exists and is a finite value, the sequence or series is said to converge. If the limit does not exist or is an infinite value, the sequence or series is said to diverge.

What is the importance of convergence or divergence?

Convergence and divergence play a crucial role in mathematics and science, particularly in calculus, analysis, and physics. They help us understand the behavior of sequences and series and determine the convergence or divergence of functions, integrals, and differential equations. They also have applications in real-world problems, such as in modeling physical systems and predicting their behavior.

How does convergence or divergence relate to the real world?

Convergence and divergence have many real-world applications. For example, they are used in economics to model and analyze economic trends, in physics to understand the behavior of physical systems, and in engineering to design and optimize structures. They also have applications in computer science and data analysis, where they are used to analyze and process large datasets.

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