Solve A: Evaluating L'Hospital's Rule for k→0

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The discussion revolves around evaluating the limit of the equation A as k approaches 0, specifically using L'Hospital's Rule. The initial attempt to apply L'Hospital's Rule to the second part of the equation led to an incorrect conclusion. The correct application reveals that the limit of the velocity, as k approaches 0, results in -49t/5. Participants clarify that the first part of the equation also requires careful consideration, as it contributes to the overall limit. Ultimately, the correct limit is established as k approaches 0, highlighting the importance of precise calculations.
glid02
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I have the equation A
44*e^(kt/5)+49((1-e^(kt/5))/k)

and I'm supposed to evaluate as k-->0

I think I'm supposed to apply l'hospital's rule to the second part of the equation, which would give
49*((1-t/5*e^(kt/5))/1)
which as k-->0 is
49*(1-t/5)

so the whole thing as k-->0 is
44+49*(1-t/5)

This isn't right, and I also tried l'hosital's rule on the first part of A, which would give 44*t/5 and this isn't right either.

What am I doing wrong?

Thanks.

Here's the whole question, in case I'm not reading it right:
Find the limit of this velocity for a fixed time t_0 as the air resistance coefficient k goes to 0.
 
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You have, by L'Hopital's rule:
\lim_{k\to{0}}49\frac{1-e^{\frac{kt}{5}}}{k}=\lim_{k\to{0}}49\frac{-\frac{t}{5}e^{\frac{kt}{5}}}{1}=-\frac{49}{5}t
 
Oh yeah, that 1 should've disappeared from what I found.

Thanks a lot.
 
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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