Homework 20

Details

Points	Problem	Comments
10	7.9	You are trying to prove that the closed formula given in Example 7.82 is correct, using the fact that fn is defined recursively by fn = fn-1 + fn-2. Don't forget the base cases! The hint is telling you that 1+(1+√5)/2=[(1+√5)/2]2 and 1+(1-√5)/2=[(1-√5)/2]2. It's up to you to figure out why this is helpful. If you start doing the algebra, you should get to a step where that formula helps.