Let P =
[n ]
[
] [tan{(pie-4)/4+(1+1/n)}
a]
n
Let t = 1 / n When n tends to infinity, t tends to 0
ln P = log [ tan { pie/4 - 1 + ( 1 + t ) } ^ a ] / t
Put t = 0 and the above limit turns out to be in 0/0 form. So apply L.Hospital in order to evaluate the limit.
ln P
=
[t ]
[0] [sec
2 { pie/4 + t } ^ a .a ( pie / 4 + t ) ^ (a-1)] / [ tan { pie/4 + t} ^ a ]
Put t = 0 to find ln P and hence evaluate P