If 3rd,4th,5th,6th term in the expansion of (x+alpha)n be respectively a,b,c and d, prove that b2-ac/c2-bd=4a/3c..
Given expansion is:
Again, dividing (1) by (2) and (2) by (3), we get
Now subtracting 1 from both sides of equation (4) and (5) as:
Again, on dividing (6) by (7), we get
On multiplying (5) by (8), we get
The RHS of equation (9) is 5a/3c not 4a/3c.
Please recheck it.