The interval in which  x (> 0) must lie so that the greatest term in the expansion of (1 + x)2n  n has the greatest coefficient is

The greatest coefficient in the expansion of (1+x)2n is 2nCn We are given  2nCnxn is the greatest  term ∴   2nCn−1xn−1<2nCnxn 2nCn+1xn+1<2nCnxn⇒ 2nCn−1 2nCn