What substitution can be used to solve this integral?

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The integral in question is int(cos(x)/sin^2(x) dx). The suggested substitution is u = sin(x), which leads to du = cos(x)dx. This transforms the integral into int(1/u^2) du, simplifying the process. The solution to the integral is -1/sin(x), indicating that the initial approach was correct but perhaps overlooked the straightforward substitution method. Understanding substitution techniques is crucial for solving integrals efficiently.
Bazzinga
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So I've gotten the integral that I'm doing now down to:

int(cos(x)/sin^2(x) dx)

I looked it up on one of those online integral calculators to get me on the right track, and the answer is:

-1/sin(x)

It seems so simple, what am I missing?
 
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An ordinary substitution will do here: u = sin(x), du = cos(x)dx. Then your integral is
\int \frac{du}{u^2} = \int u^{-2}du
 
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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