# Friday Five for May 6, 2016

The Friday Five has spring fever. It’s not going to lie; it was thinking about calling in sick, but then realized that finding a sub was probably more work than showing up and getting the work done itself.

Even so, the Friday Five’s mind was on the out-of-doors this week. It got to thinking about running, then running very fast, and pretty soon it was recommending the following:

## Modeling the Fastest Mile

Usain Bolt ran 100 meters in 9.58 seconds. How can we use this to predict the world record for the fastest mile ever run? Proportionality meets human stamina in this gem from Michael Fenton.

## Piecewise Linear Functions

Paradoxically, piecewise-defined functions are some of the most useful tools in mathematics, and one of the hardest principles for many students to wrap their minds around. Mr. Unger gives us all a hand with this activity that reduces the complexity of the relationship between notation and graph, and that puts the power of the Desmos graphing calculator into students’ hands.

## Point Mapping Activity

Suzanne Von Oy is back in the Friday Five with this activity that has students move between two notations: that for transforming functions (e.g. g(x) = f(x-2)+3) and that for transforming points (e.g. (x1+2,y-7))

## Slope of a Purple Segment

Another mind-bender from the desk of Luke Walsh. If you have never worked through one of Luke’s activities, you’re in for a treat if you start with this one. Domain restrictions, slopes, perpendicular bisectors….all this and more in an activity that slowly but surely ratchets up the complexity and challenge. It’s a ton of fun—you and your Algebra 2 or precalculus students should get on it right away!

## Using Derivatives to Locate Extreme Values

Weylon White offers up a great activity that builds the Extreme Value Theorem on top of students’ intuitions. If you liked our Intermediate Value Theorem activity, then this one will be right up your alley, too.

Think about it this way: If you use one of these five activities in class next week, you’ll have just a little bit less lesson planning to do between now and then, and just a little bit more time outside smelling whatever flowers are blooming in your neighborhood.

Enjoy.