Write the sum without sigma notation and evaluate it?

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SUMMARY

The discussion focuses on evaluating the finite sum represented by the notation ∑ 2cos(π/k) for k ranging from 1 to 4. The explicit evaluation results in the expression 2cos(π/1) + 2cos(π/2) + 2cos(π/3) + 2cos(π/4). Participants clarify that understanding the sigma notation is crucial, as it involves substituting values of k and summing the results. The final answer is derived directly from these substitutions.

PREREQUISITES
  • Understanding of sigma notation in mathematics
  • Familiarity with trigonometric functions, specifically cosine
  • Basic knowledge of finite sums and series
  • Ability to perform substitutions in mathematical expressions
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femmed0ll
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∑ 2cos (π/k)
k = 1

i have the answer..but all i need it the steps on how to figure it out!
thanks!
 
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It's a finite sum...

[tex]\sum_{k=1}^4 2 \cos(\pi/k) = 2 \cos(\pi/1) + 2 \cos(\pi/2) + 2 \cos(\pi/3) + 2 \cos(\pi/4)[/tex]

...
 
It is not a question of "figuring it out", it is just a question of knowing what that notation means.

It means exactly what adriank said: replace the "k" in [itex]cos(\pi/k)[itex]with 1, 2, 3, and 4 and then add.[/itex][/itex]
 

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