Hey ThanhPhungLe1112.
Hint for 1: What is the formula for the first three terms of a binomial expansion? Can you get results for a in terms of two of the coefficients?
Hi,
I have a couple of homework questions, can anyone help me please?
1) Given that the expansion of (1+ax)^n begins 1+36x+576x^2, find the values of a and n.
2) Determine the coefficient of p^4q^7 in the expansion of (2p-q)(p+q)^10.
3. How to expand the entire trinomial: (10+9x^{3}+8/(3x^{5}) )^{3}
Thank you very much
um...This is what I have for number 1. I'm not sure if it's right
_{n}C_{0} (1)^{n}(ax)^{0} + _{n}C_{1} (1)^{n-1}(ax)^{1} + _{n}C_{2} (1)^{n-2}(ax)^{2}
(1)(1)(1) + _{n}C_{1} (1) (ax) + _{n}C_{2} (1) (a^{2}x^{2})
_{n}C_{1} (ax) = 36x
_{n}C_{1} (a) = 36
_{n}C_{2} (a^{2}x^{2}) = 576x^{2}
_{n}C_{2} (a^{2}) = 576
But then from here on, I'm stuck.
Please help!
Thanks,
Phung
PS: I know that somehow you have to use the factorials formula, but I don't know how to apply it in this case.
okay, Thanks I got the answer for that problem.
But I have another assigment. So I was supposed to make a powerpoint explaining how to expand trinomials. I made my powerpoint, but when we did peer review in class this morning, some people said that I made a mistake. I can't figure out what I did wrong though so can you please help me by viewing this powerpoint and point out the mistake? I don't think it's calculation error, because I don't think they had times to check calculations so I must have solved it wrong.
This is do tomorrow so can you please help me????
* I know I made a mistake. The answer was supposed to be 1000 + 2700x^3.........
but beside that, is there anything else that I need to fix?