Help with double integral problems

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The discussion centers on a double integral problem involving the integration of cos(x^2) over a specified region. The original poster struggles with the integration, noting that it leads to a special function that seems too advanced for their course level. A suggestion is made to visualize the region and reverse the order of integration to simplify the problem. This approach helps clarify the solution process. Overall, the thread emphasizes the importance of understanding the geometric interpretation of integrals in multivariable calculus.
elvishatcher
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Can someone explain to me how I would arrive at this answer?:
http://www.wolframalpha.com/input/?...m+x=y+to+x=sqrt(pi/2)+and+y=0+to+y=sqrt(pi/2)

This double integral problem came up in a practice test I was taking, and I just can't figure it out. I tried integrating it but couldn't figure out how to integrate cos(x^2)dx and when I put that into Wolfram Alpha it said it involved some special function that seems much too advanced for the level of the course the test is from (it's from a first year multivariable calculus class). Thanks!
 
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elvishatcher said:
Can someone explain to me how I would arrive at this answer?:
http://www.wolframalpha.com/input/?...m+x=y+to+x=sqrt(pi/2)+and+y=0+to+y=sqrt(pi/2)

This double integral problem came up in a practice test I was taking, and I just can't figure it out. I tried integrating it but couldn't figure out how to integrate cos(x^2)dx and when I put that into Wolfram Alpha it said it involved some special function that seems much too advanced for the level of the course the test is from (it's from a first year multivariable calculus class). Thanks!

Draw the region then use your picture to reverse the order of integration.
 
Aha, got it. Thanks much.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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