Pure Math - Series (AS)

[Diablo]

Hola!

Help will be appreciated with the following question:

If the first three terms in the expansion of (1 + kx)ⁿ in ascending powers of x are 1-6x+33/2x² , find the values of k and n.

I'm new to this chapter and the ncr stuff, so I can't really apply Algebra in such questions .

Thanks!

[Saladin]

you'r first 3 terms are confusing. Please clearly state the first 3 terms.

[astarmathsandphysics]

One mo

[astarmathsandphysics]

(1 + kx)n in ascending powers of x are 1-6x+33/2x2 , find the values of k and n.
(1 + kx)n=1+nkx+n(n-1)/2 k^2 x^2=1-6x+33/2x^2
nk=6 andn(n-1)/2k^2=33/2
kn=6 so k^2=36/n^2 and n(n-1)k^2=33 so n(n-1)*36/n^2==36-36/n=33 so 3=36/n and n=12 and thenk=1/2

[Diablo]

Thanks for your replies. I managed to solve it earlier today after going through some examples.

Thanks Again