### Golden Powers

You add 1 to the golden ratio to get its square. How do you find higher powers?

### Continued Fractions I

An article introducing continued fractions with some simple puzzles for the reader.

### Fibonacci Factors

For which values of n is the Fibonacci number fn even? Which Fibonnaci numbers are divisible by 3?

# Fibonacci Fashion

##### Age 16 to 18 Challenge Level:

$F_n={1\over\sqrt5}(\alpha^n-\beta^n)$ where $\alpha$ and $\beta$ are solutions of the quadratic equation $x^2-x-1=0$ and $\alpha > \beta$ is the explicit formula for the $n$th Fibonacci number as given in this question.

The Golden Ratio is one of the roots of the quadratic equation and this explains the many connections between Fibonacci numbers and the Golden Ratio.

This problem complements the material in the article The Golden Ratio, Fibonacci Numbers and Continued Fractions
For a sequence of, mainly more elementary, problems on these topics see
Golden Mathematics

See this article if you want to know more about the method of proof by mathematical induction.