Prove from the defintion of nPr (as in nPr = n!/(n-r)!) that
(n+1)/Pr = nPr + r.nP(r-1)
and show that nPr = (n-2)Pr + 2r. (n-2)P(r-1) + r(r-1) x (n-2)P(r-2)
if anyone could give me some techniques or some help solving these types of questions i would really appreciate it ! thankyou =D
Follow Math Help Forum on Facebook and Google+
Now we use this formula to prove the second identity.
thanx so much for your help !
View Tag Cloud