defence exam SSB Head Constable (Communication) 2023 Mock Test Mathematics Binomial Theorem Binomial Expansion
The coefficient of xn in the expansion of \(\rm \left(1+x\over1-x\right)^2\), is:
1
n+1Cn + nCn-1 + n-1Cn-2
2
n+1Cn + 2nCn-1 + n-1Cn-2
3
n+1Cn + n+2Cn-1 + n+3Cn-2
4
n+1Cn + 2 × nCn-1 + n-1Cn-2