Mathematics · important
Useful permutation recurrence 1 for JEE
Meaning of P(n,r) and C(n,r)
Formula
\(\,{}^nP_r=n\,{}^{n-1}P_{r-1}\)
Variables: \(n,r\) are integers.
Conditions: \(1\le r\le n\).
Recursive counting and simplification.
Mathematics · important
Meaning of P(n,r) and C(n,r)
Formula
\(\,{}^nP_r=n\,{}^{n-1}P_{r-1}\)
Variables: \(n,r\) are integers.
Conditions: \(1\le r\le n\).
Recursive counting and simplification.