Find the Mistake in Homework Statement

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Homework Help Overview

The discussion revolves around evaluating the integral of COS(√x) from 0 to π². Participants are examining the correctness of the original poster's solution and the discrepancies with a referenced answer.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the original poster's substitution method and the resulting expressions. Questions arise regarding the validity of the final results and the potential for errors in the calculations or assumptions made.

Discussion Status

There is an active exploration of different results obtained by participants, with some suggesting that the original poster's interpretation may be incorrect. Guidance is offered regarding checking substitutions, but no consensus on the correct answer has been reached.

Contextual Notes

Participants are questioning the validity of the original answer compared to a book's reported result, indicating possible discrepancies or errors in the original problem statement or solution process.

ddr
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Homework Statement



π^2
4
∫ COS(√x) dx
0

Homework Equations





The Attempt at a Solution



t=√x ; x=t^2 ; dx= 2t

π
2
∫ COSt · 2t dt = [SINt · 2t ] - ∫ 2SINt dt = π +2
0

yes but.. where is the mistake?
'cause the result is: π/2 - 1

thanx a lot
 
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I get π +2. What makes you think the answer is π/2 - 1?
 
The answer should be [itex]\pi - 2[/itex]. Check the substitutions in the final step.
 
Neutrino is right, the result is π - 2, but why does the book report a π/2 - 1 result?
 
A typo, perhaps?
 

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