Presume that $α_1$ and $α_2$ are solutions to the quadratic function, prove that $α_1^n$ and $α_2^n$ fulfill the recursive formula
Quadratic function: $x^2 = bx + c$
Recursive formula: $ a_{n+2} = ba_{n+1} + ca_n$
I'm honestly very lost on this one
Multiply $\alpha^2 = b\alpha + c$ by $\alpha^n$ to get $\alpha^{n+2} = b\alpha^{n+1} + c\alpha^n$ for all $n \in \mathbb N$.
Ah I was making it way more complicated than I had to...
If I could ask a follow up question:
Presume that $α_1 ≠ α_2$ and that $a_1$ and $a_2$ are given. Prove that there is always coefficients $r$ and $s$ so that:
$rα_1 + sα_2 = a_1$
, $rα_1^2 + sα_2^2 = a_2$
am I supposed to use the recursion condition to prove this?
– JohnDoe Feb 01 '18 at 15:49