Monday, May 9, 2011

f(u) Calculus Song!

In case you haven't seen it, I made a song parody about some of the basic derivatives rules in Calculus to the tune of Ceelo's "Forget you."   Enjoy!

updated with lyrics:

I see you derivin' in class during calc-u-lus
And you've got f(u)
Which you want to find the derivative of,
it's just f '(u) and a du too,
it's just the chain rule,
a great cal-cu-lus tool
and you use it when...(you use it when)
When there's an inside and an outside that you can write as,
(ooo ooo ooo)

Another derivative tool,
is the product rule.
And I know you can get it done
The slope of the product
of functions 1 and 2
is 1d2 plus 2d1.
I pity the foo-ooo-oool
who forgets the product rule
(oh, that's how you get it done)
(it's just 1d2 plus 2d1)
There's just one more rule
Wait... what was the chain rule again?


For quotient, quotient, quotient you don't have to, have to pull out your hair,
(your hair, your hair, your hair)
Cause it's just low di high minus hi di low all over low squared
(Low squared, low squared, low squared)
To find dy dx dy dx dy dx baaa-aaa-aaaby,
But what about, that dang chain rule?


Tuesday, May 3, 2011

How I see exponent rules (and log rules)

Exponent rules can be difficult to remember, and memory has never been one of my strong suits. When I was in high school myself learning exponent rules, I would get mixed up just trying to remember them individually, and had to come up with a different way of thinking to condense it into one idea.  What I came up with deals with the levels of complexity of operations:
So, you've got your simple functions on the bottom, multiplication and division are a little more complex, and then exponents and roots are more complex. The actual chart above I created after the fact when trying to explain the idea to students later in life.  So, basically when it came to exponent rules all I had to remember was to "go down a level" of complexity.
So multiplication becomes addition, division becomes subtraction, an exponent to an exponent becomes multiplication and a root with an exponent becomes division. The chart also helps for remembering when to distribute. Operations distribute on to the tier below them. (exponents distribute over multiplication and division for example)  

My results with trying to get students to see the same thing I do has been mixed.  I usually end up doing an exploratory learning exercise with exponents , then going through the rules individually and only quickly going through this chart idea on the side.  While it doesn't really connect with every student, when a particular student gets the rules mixed up it can really help because it at least gives them a plan rather than just relying on straight memorization.

Later on, when I learned about logs it turned out that log rules (surprising to me at the time, not so much anymore) followed along the same lines, with exponents becoming multiplication, multiplication become addition, etc. 

Anyone else ever think of it this way?  Have some other strategy for helping students get exponent rules straight?  Let me know!