Answer:
a direct variation is a relation that is of the form y = mx
- example of a direct variation: y = 2x
a partial variation is is a relation that is of the form y = mx+b
- example of a partial variation: y = 2x + 1
- a non-linear function doesn't have a constant rate of change
- the graph for a non-linear relationship is curved
- a non-linear curve may show a positive or a negative relationship
