MathCastle
PrecalculusSuperchallengeSystems, Matrices, and Determinants

Systems, Matrices, and Determinants · Superchallenge problem

Two sequences start with a0=1a_0=1, b0=0b_0=0 and satisfy

[an+1bn+1]=[2112][anbn]for n≥0.\begin{bmatrix}a_{n+1}\\b_{n+1}\end{bmatrix}=\begin{bmatrix}2&1\\1&2\end{bmatrix}\begin{bmatrix}a_n\\b_n\end{bmatrix}\quad\text{for } n\ge0.

Find a10a_{10}.