A. n(n+1)/2
B. n(n-1)/2
C. (n-1)(n+1)/2
D. n(n+2)/2
Middle term in the expansion of (2x-3/x)15is
If the coefficients of 2nd, 3rd, 4th terms in the expansion of (1+x)2n are in A.P. then
If a is small in comparision with x, then (x/x+a)1/2+( x/x-a)1/2
(√2+1)6+(√2-1)6=
3.C0-5.C1+7.C2-9.C3+…………(n+1) terms =
Larger of 199100+200100and 201100 is
The coefficient of x7 in (1-2x+3x2-4x3+……..∞)-4 is
The 3rd term of 4 (3x-y3)is
5th term of (2x2+3/x)5 is 10. Then x=
The coefficient of xn in(1+x)2/(1-x)2 is