1. Section 1.6 Mathematical Modeling
direct variation
direct variation as nth power
inverse variation
joint variation

2. for some nonzero constant k
Direct Variation
y varies directly with x
y is directly proportional to x
y = kx,
for some nonzero constant k
k is the constant of variation or the constant of proportionality
example on worksheet

3. Direct Variation as nth Power
y varies directly as the nth power of x
y is directly proportional to the nth power of x
y = kxn ,
for some nonzero constant k
example on worksheet

4. for some nonzero constant k
Inverse Variation
y varies inversely as x
y is inversely proportional to x
y=k/x ,
for some nonzero constant k
example on worksheet

5. for some nonzero constant k
Joint Variation
z varies jointly as x and y
z is jointly proportional to x and y
z = kxy ,
for some nonzero constant k
example on worksheet