# Dedicate yourself and you will find yourself

Geometry Level pending

$s = 1- \cos a + \cos^2 a - \cos^3 a + \cdots \\ r = 1-\sin a + \sin^2 a - \sin^3 a + \cdots$

We are given the two equations above. State the expression below in terms of $$r$$ and/or $$s$$.

$1 - \sin a \cos a + \sin^2 a \cos^2 - \sin^3 a \cos^3 a + \cdots$

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