Monday, 22 May 2017

combinatorics - An application of this binomical identity binomnk=binomn1k+binomn1k1

I need a clarification on this manner, in terms of "When do I apply this form of



identity". I managed to proove it algebraically and combinatorially, using



"Pascal's triangle". so a proof is not needed. However I am not comprehending what it's




application in terms of combinatoric(or any) exersice.



\binom{n}{k}=\binom{n-1}{k}+\binom{n-1}{k-1}

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real analysis - How to find lim_{hrightarrow 0}frac{sin(ha)}{h}

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