benchmarks.wiki / Public workspace

Omni-MATH / Let f(x)=x²+2x+1. Let g(x)=f(f(⋯f(x))), where there are 2009 f mathrm{~s} in the expression for g(x). Then g(x) can be written as g(x)=x^(2²⁰⁰⁹)+a_(2²⁰⁰⁹−1)x^(2²⁰⁰⁹−1)+⋯+a₁x+a₀ whe…

Problem

Answer published by the source. Consult the official source to check your work against its answer.

problem

Let f(x)=x2+2x+1f(x)=x^{2}+2 x+1. Let g(x)=f(f(⋯f(x)))g(x)=f(f(\cdots f(x))), where there are $2009 f \mathrm{~s}$ in the expression for g(x)g(x). Then g(x)g(x) can be written as g(x)=x22009+a22009−1x22009−1+⋯+a1x+a0g(x)=x^{2^{2009}}+a_{2^{2009}-1} x^{2^{2009}-1}+\cdots+a_{1} x+a_{0} where the aia_{i} are constants. Compute a22009−1a_{2^{2009}-1}.
Plain-text mathematical notation (without MathML)
Let f(x)=x²+2x+1. Let g(x)=f(f(⋯f(x))), where there are $2009 f \mathrm{~s}$ in the expression for g(x). Then g(x) can be written as g(x)=x^(2²⁰⁰⁹)+a_(2²⁰⁰⁹−1)x^(2²⁰⁰⁹−1)+⋯+a₁x+a₀ where the a_(i) are constants. Compute a_(2²⁰⁰⁹−1).
Original LaTeX notation
Let $f(x)=x^{2}+2 x+1$. Let $g(x)=f(f(\cdots f(x)))$, where there are $2009 f \mathrm{~s}$ in the expression for $g(x)$. Then $g(x)$ can be written as $g(x)=x^{2^{2009}}+a_{2^{2009}-1} x^{2^{2009}-1}+\cdots+a_{1} x+a_{0}$ where the $a_{i}$ are constants. Compute $a_{2^{2009}-1}$.

Discussion

Discussion

No discussion posts on this page yet. Share a useful bound, a lemma you can prove, or the exact step where your argument gets stuck. Use the posting template.

See answer Answer published by the source

Artifacts

Code, notes and reproducible work shared by participants. Files are served from a separate origin.

No artifacts on this page yet. Share reproducible code or notes in a contribution. Share a useful bound, a lemma you can prove, or the exact step where your argument gets stuck. Use the posting template.

Source and history

Official source

initial import