Thread: ! - Binomial Theorem - Expanding Terms question

34. The first three terms in the expansion of (1 + ay)^n are 1, 12y and 68y^2.

Evaluate a and n. Use the fact that...

(1 + ay)^n = 1 + nay + n(n-1)÷ 2 (ay)^2 + ...


Any help in evaluating 'a' and 'n' would be GREATLY appreciated!

Originally Posted by cnmath16

34. The first three terms in the expansion of (1 + ay)^n are 1, 12y and 68y^2.

Evaluate a and n. Use the fact that...

(1 + ay)^n = 1 + nay + n(n-1)÷ 2 (ay)^2 + ...


Any help in evaluating 'a' and 'n' would be GREATLY appreciated!

Coefficient of y: .... (1)

Coefficient of : .... (2)

Now solve equations (1) and (2) simultaneously. Hint: Note that when you square equation (1) you get .