number theory questionq http://prntscr.com/58jn7n
@ganeshie8 @KamiBug @Miracrown @Kainui
what is a non-constant polynomial mean
one that has terms other than ax^0
means f(x)=g(x)I(x) such that \(g(x)=\sum a_ix^i\) \(I(x)=\sum b_jx^j\) and for all b's and a's they are 1 or 2 ( depend on binomial theorem )
basically you want to find the ordered pairs such that the polynomial is not prime
and yes i and j are not zero
f(x) = g(x) * h(x) the degrees of g and h need to be atleast 1
why such that the polynomial is not prime
this is what it asked for :D
ok i see
why didnt they just write that out
takes too many words if u use degree and other stuff to state the problem
hmm lets carry on
interesting problem
man us 3 are the only ones that stick it out with these problems lol
so it is in this form\[f(x) = x^n + x^{n-1} + \cdots + 2(x^m+x^{m-1}+\cdots+1)\]
yeah
0<=M<=N<=25
yeah m<n is implied in above split up
0<=m<n<=25
m=n-k
ya okay bascally in that form
oh i see
okay i see where that combinatorics is gonna come out
for exampl,e of f(x)=g(x) * h(x) for g(x)=x then u are gonna have that same coefficients , and degree just decreased by 1
\[\begin{align}f(x) &= x^n + x^{n-1} + \cdots + 2(x^m+x^{m-1}+\cdots+1)\\~\\ &=(x^n + x^{n-1} + \cdots +x+ 1)+ (x^m+x^{m-1}+\cdots+x+1)\\~\\ &=\dfrac{x^{n+1}-1}{x-1}+\dfrac{x^{m+1}-1}{x-1}\\~\\ \end{align}\]
of f(x)=x^n+x^n-1..+2x^m+x^m-1..+2 for g(x)=x,x^2,x^3,.... h(x) for g(x)=x h(X)=x^n-1+x^m+2*x^m-1...+2/x <--- problem with this one
Recall the formula \[x^{ab}-1 = \left(x^a\right)^b-1 = (x^a-1)(x^{a(b-1)} + x^{a(b-2)}+\cdots +x + 1) \]
where did that formula come from
we use the same idea as here : http://math.stackexchange.com/questions/966747/show-that-if-a-positive-integer-n-is-composite-then-rn-frac10n-1/966765#966765
that follows from \(\large x^n-1 = (x-1)(x^{n-1} + x^{n-2}+ \cdots +x+1)\) plugin \(n=ab\)
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