1. Direct and inverse variation
y = k x
y = kx
k is like m
meaning it is the slope Or
the constant of variation
This graph would be linear
This graph would be exponential
This graph has to go through the origin and makes a straight line
This graph may or may not go through the origin and will not make a straight line

2. Y = -2X
Y - intercept
0,0
X - intercept
0,0 X y 1 -2 2 -4 3 -6

3. Domain Range Y = 2/x or Y = (2)x X y -3 ⅛ -2 ¼ -1 ½ 1 2 4 3 8 Y X1 2 4 3 8 X
Domain
Range
All real numbers
All positive
real numbers

4. write a direct variation problem when y = 20 and x = 10
y = kx
20 = k·10
k = 2
y = 2x

5. write an inverse variation problem when y = 20 and x = 10
y = k x
20 = k 10
k = 200
y = 200 x

6. ixl.com r1 r2 r4 r6 r7 r8