How Do You Solve Differential Equations Using Integration by Quadratures?

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Homework Statement



I cannot get my head around these equations...
\dot{x}(t)=-sin y(t)

\dot{y}(t)=-\frac{cos x(t)}{sin x(t)} cos y(t).

They are to be solved with integration by quadratures. :S But I am not at all familiar with that technique and I can't find any tutorial for it.

Since I have never heard about it before i can't make an attempt either! :(
 
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http://mathworld.wolfram.com/Quadrature.html

I don't know what exactly you need, but I am guessing you differentiate your first equation wrt t and substitute the result in the second equation to get an equation in one variable which you solve, and then use that result to find the solution for the remaining variable.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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