bionomial expansion

Question 1

Year 13 with brackets to a power : (1+ax)^n

Answer 1

1+ anx + n(n-1)((ax^2)/2!) + n(n-1)(n-2)((ax^3)/3!)

Question 2

How do you test for validity in a binomial question

Answer 2

Insert all values of x being tested into ax from the binoial in form (1+ax)^n. Only values -1

Question 3

calculate probability of having an exact amount of outcomes

Answer 3

P(X=r) = nCr (p^r) (1-p)^n-r