Solving A Differential Equation

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The discussion focuses on solving a differential equation involving the relationship between y and x. The integral of both sides leads to the equation y² + sin(y) = 2x³, which requires determining the constant of integration. When substituting x = 1 and y = π, the constant C is found to be π² - 2. The final expression for x in terms of y is derived as x = ((y² + sin(y) - π² + 2)/2)^(1/3). The participants confirm the correctness of their calculations and the importance of including the constant of integration.
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Given the two equations:

y(1) = \pi

\frac{dy}{dx} = \frac{6x^{2}}{2y + \cos{y}}

Solve for x:

\begin{align*}<br /> \int(2y+\cos{y})dy &amp;= \int(6x^{2})dx\\<br /> y^{2} + \sin{y} &amp;= 2x^{3}\\<br /> \end{align*}

But in order to set a value to the function y, I need some way to exclude y and then plug in 1 for x. How do I exclude y when it's in two separate terms?

Or is there an easier way to do this?
 
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When x = 1, y = pi. Does that make it any simpler? Don't forget the constant of integration
 
Oh right! I forgot the C. That's why it wasn't working. I'm silly without my morning coffee... Haha. Thanks.
 
I just need to make sure I did this correctly.

\begin{align*}<br /> (\pi)^{2} + \sin{(\pi)} &amp;= 2(1)^{3} + C\\<br /> C &amp;= \pi^{2} - 2\\<br /> \\<br /> 2x^{3} + \pi^{2} - 2 &amp;= y^{2} + \sin{y}\\<br /> 2x^{3} &amp;= y^{2} + \sin{y} - \pi^{2} + 2\\<br /> x &amp;= (\frac{y^{2} + \sin{y} - \pi^{2}}{2} + 1)^{\frac{1}{3}}<br /> \end{align*}
 
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I guess the step before the last would do just fine.
 
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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