1. 2.2 Direct Variation
P68-70

2. Direct Variation: a function that
can be written as y = kx, where k
is not zero. (a line that goes through (0,0))
Constant of variation: the ratio
(the slope)

3. Ex 1) Does y vary directly with x? If so,
find the constant of variation (k).

4. Ex 2) Determine if y varies directly
with x. If so, find the constant of variation.
a) 3y=7x
b) 7y=14x+7

5. Ex 3) Suppose y varies directly with x,
and y=9 when x=-15. What is y
when x=21?

6. Ex 4) A salesperson’s commission varies
directly with sales. For $1000 in sales,
the commission is $85. What is the
commission for $2300 in sales?

7. Ex 5) What is the graph of each
direct variation equation? a) b)