1. The curve C has parametric equation x = sin t, y = sin 2t, 0 ≤ t ≤ pi/2.

If the region is revolved through radians about the x-axis, find the volume of the solid formed.

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So Volume =

Then how could I integrate this?

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2. Find a general solution of the following differential equation.

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So far I did,

But this is not right ans. The right ans is

So where did I wrong?

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