Integration by Parts: Improper Integral

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Using integration by parts is not necessary at this stage of the integral evaluation. Instead, rearranging the integrand into simpler components can facilitate the integration process. The expression can be split into u^(1/2) and 3u^(-1/2), making it easier to integrate. This approach simplifies the calculations significantly. The discussion emphasizes the importance of recognizing algebraic manipulation in integration techniques.
ggcheck
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I used u substitution to get to this point:

\lim_{R\rightarrow\ 3-}} \int_{-3}^{R-3} (\frac{u + 3}{sqrt{u}}) du

is the only way to proceed from here using integration by parts?
 
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ggcheck said:
I used u substitution to get to this point:

\lim_{R\rightarrow\ 3-}} \int_{-3}^{R-3} (\frac{u + 3}{sqrt{u}}) du

is the only way to proceed from here using integration by parts?

If your calculations are correct up to this point, i do not think you need to use integ by parts. Simply just try to rearrange the integrand like this

(u+3)/u^1/2= u/u^1/2 +3/u^1/2 = u^1-1/2 +3u^-1/2 and i guess you will be fine!
 
sutupidmath said:
If your calculations are correct up to this point, i do not think you need to use integ by parts. Simply just try to rearrange the integrand like this

(u+3)/u^1/2= u/u^1/2 +3/u^1/2 = u^1-1/2 +3u^-1/2 and i guess you will be fine!
ahhh, I didn't think to break up the fraction, for some reason I missed that

thanks :)
 
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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