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It's the end of a Physics Problem. 2 Forces are equal, one is proportional to $\sin\phi$ the other to $$\frac{\cos\phi}{\text{distance}^2}$$ distance is proportional to $\sin\phi$ $$$$ I'm stuck at this last equation $$\frac{\sin^3\phi}{\cos\phi}=c$$

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Try restating all the "proportional to"'s as equalities, by inserting proportionality constants c_n. Then collect the named constants together and replace them with "c".

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But there is only one c for all the equals left. I don't get what u mean – whateverguy Apr 20 '13 at 10:45
Try following the recipe instead of throwing your hands in the air saying "I can't!" – Pieter Geerkens Apr 20 '13 at 11:09

I solved it to $$\phi=\arcsin x$$ $$\frac{x^3}{\sqrt{1-x^2}}=c$$ $$\frac{x^6}{1-x^2}=c^2$$ But I think one can only solve this numerical

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