1. 2.3: Direct Variation
If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away.

2. Direct Variation
Ex1) Determine the direct variation equation of the given graph.
Characteristics of Direct Variation: 2

3. Using a Table
Does y vary directly with x in the following examples? (Check the ratio y/x)
Ex2)
Ex3) x y -1 3 2 -6 5 15 x y 7 14 9 18 -4 -8 3

4. Using Equations
Does y vary directly with x in the following equations? (Can the equation be written in the form y = kx ?) 4

5. Perimeter
Ex6) The perimeter of a square varies directly as the length of a side of the square.
a) Write a direct variation equation.
b) Find the constant of variation.
c) Find how long a side of the square must be for the perimeter to be 64 cm. 5

6. Using Proportions
Ex7) Suppose y varies directly with x, and y = 15 when
x = 27. Find y when x = 18. 6

7. Daniel, eh, son…. What does that sign say?!?!?
2.3: Direct Variation
HW: # 1-19 odd, 23, 24-27, 33, 34, 46, 47
Daniel, eh, son…. What does that sign say?!?!?