Man’s mind, once stretched by a new idea, never regains its original dimensions.
— Oliver Wendell Holmes
When things get too complicated, it sometimes makes sense to stop and wonder: Have I asked the right question?
— Enrico Bombieri
As you probably know, I wear my heart on my sleeve:
Well, I took the golden opportunity (ha!) to bring the golden ratio into Calc 2 this week, using it (and its little pal
) to find a closed formula for the
-th term of the Fibonacci sequence.
The ubiquitous Fibonacci sequence! It’s something you may have encountered out in the wild. You know, it goes a little like this:
so
And let’s say for some reason, you need to cook up . I hope you have some time on your hands if you’re planning to add all the way up to that. Instead, wouldn’t it be nice if we had a simple formula that we could use — i.e., a formula that was not recursive — to figure out the
-th Fibonacci number?
Luckily, such a formula exists, and there are lots of ways to find it. In this post, we’ll find it using power series. Read on, brave blogosphere traveler.
As you might imagine, starting a “real” job entails a certain amount of stress. Suddenly, your support network of graduate student friends is dispersed across the country, and you’re one of a handful of junior faculty across a smattering of disciplines. So, you have to find new outlets for your stress. Aside from climbing at the rock wall a few times a week, I’ve found that it’s incredibly helpful to have a creative outlet. This brings me to…