1. Collect homework.
2. To introduce Linear Approximations or Differentials:
If you stretch a rope tightly around the earth, and then increase the length of the rope by about 6 feet (i.e, you increase the circumference by 6.28 feet), how far would the rope be above the ground?
Have students write down their guess.
Answer is one foot!
How would this change if the rope were tied around a ball that has a diameter of 1 foot?
To illustrate, take a piece of string and have students make a circle with it on the floor.
Then take another piece of string (6 feet 3 inches longer than the first) and make a circle outside the first. Measure the change in the radius.
3. Example
4. Ten Commandments of Mathematics