well general method i can give u a very good idea
suppose a function be xm
then the nth derevative will be like this see
for the nth derevative
we multiply and divide by n!
this is the method
using this we can calculate for
general formula of nth derivative of (ax+b)-r is
(-1)n (n+r-1)! (a)n / (ax+b)n+r (r-1)!
(as wriiten by prasad)
for such problems we need to find a relation between the derevatives!!
as a function of the number of times differenciated!!
these things dont come in JEE!!
all this successive differenciation and leibnitz theorum
i.e sucessive differenciation of product of two functions!!