April 3rd, 2014, 12:11 PM |
#1 |

Senior Member Joined: Nov 2013 Posts: 434 Thanks: 8 | a and b
(1+ root(2) )^2006=a+broot(2) find a^2-2b^2 |

April 3rd, 2014, 12:36 PM |
#2 |

Senior Member Joined: Dec 2013 From: Russia Posts: 327 Thanks: 108 |
This problem is outdated: it is from 2006. Next, please! Seriously, note that $\displaystyle a^2-2b^2=(a+\sqrt{2}b)(a-\sqrt{2}b)$ and try expressing $\displaystyle a-\sqrt{2}b$ similarly to how $\displaystyle a+\sqrt{2}b$ is defined. |