Mathematics · important
Useful combination recurrence 2 for JEE
Permutations and combinations
Formula
\(\,{}^nC_r=\dfrac{n}{n-r}\,{}^{n-1}C_r\)
Variables: \(n,r\) are integers.
Conditions: \(0\le r\le n-1\).
Simplifying expressions and comparing adjacent coefficients.