formulas variations questions

Question

1. Most formulas are actually examples of variation. Pick a well-known formula and describe the type of variation as well as the constant of variation, k. Example: The area A of a triangle with base b and height h is given by the formula A=½bh. So, the area of a triangle varies jointly as the base and height (both direct) with the constant of variation = ½.

Answer 1

Go to a grocery store and look at the prices for fruit.

Answer 2

Geometry has lots of formulas. Here are a couple:

Area of a circle: A = πr² where area varies directly as the square of the radius and k (the constant of variation) = π

Diameter is twice the radius: D = 2r where diameter varies directly as the radius and k (the constant of variation) = 2