Arc Length Need Verification, If Wrong, Can You Help?

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The discussion centers on verifying the arc length of the curve defined by y=1/2(e^x-e^(-x)) from 0 to 2. The formula for arc length, s = ∫√[1+(dy/dx)²] dx, is applied, leading to a complex expression. A suggestion is made to simplify the calculation by recognizing that y(x) corresponds to the hyperbolic sine function, sinh(x). This simplification could streamline the integration process significantly. The conversation emphasizes the importance of clarity in notation for accurate problem-solving.
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Homework Statement



Length of curve: y=1/2(ex-e-x) from 0 to 2


Homework Equations



s = ∫√[1+(dy/dx)^2] dx

The Attempt at a Solution



[sqrt(4+2e^(-x)+e^x)]*[-1+e^x]/[1+e^x].
= 3.323971
 
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Your notation is ambiguous. I'm guessing that your curve is,

y(x) = \frac{e^x-e^{-x}}{2}

In which case it may be useful to note that,

\frac{e^x-e^{-x}}{2} = \sinh(x)

Which (along with a hyperbolic identity) would greatly simplify your integrand.
 
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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