Question

The coefficient of the middle term in the binomial expansion in powers of x of (1 + αx)⁴ and of (1 – αx)⁶ is the same if α equals

(a) –3/10

(b) 10/3

(c) –5/3 

(d) 3/5.

Answer 1

(a) : Coefficient of middle term in (1 + αx)⁴ = coefficient of middle term in (1 – αx)⁶
Therefore, ⁴C₂α² = ⁶C₃(– α)³
=> α = - 3/10