Thread: Binomial Theorem Chapter

I am taking Gr 12 Data Management online and am really struggling to understand this chapter. One of the questions is:

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+...


I have gone over my notes and the text and dont know how go about evaluating for a and n. Any help would be greatly appreciated! Thanks in advance

Originally Posted by shell

I am taking Gr 12 Data Management online and am really struggling to understand this chapter. One of the questions is:

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+...


I have gone over my notes and the text and dont know how go about evaluating for a and n. Any help would be greatly appreciated! Thanks in advance

So you have

and so ,

and

and so .

Giving you 2 equations in two unknowns, gives , substitute this into the second equation and solve for n.

Hope this helps.