2 quick questions about direct variation?

Question

1. How can you tell whether 2 sets of data vary directly?

2. how can you tell if a line is the graph of a direct variation?

Answer 1

Hello,

1. A direct variation looks like.

Total Cost of Gasoline = Cost per Gallon * Number of Gallons.

c = k * n. So as the number of gallons (n) increases the cost (c) increases by the same factor. So if the number of gallons doubles the total cost doubles.

2. If the graph is the equation of a line like y = mx +b or y = mx then it is a direct variation.

Hope This Helps!

Answer 2

all direct variation situations start at the origin. This should help answer both of your questions.

Answer 3

y is propotional to one million/x so y = ok/x, the place ok is a few consistent or, xy=ok all of us understand that when x is -one million. y is 5. substituting in the above equation we get ok= -5 so the respond of your first query is x*y=-5 for the 2d query: z varies rapidly with y and inversely with x so z = ok*y/x, the place ok is a few consistent all of us understand that when x=3, y=12, z is two. substituting those values in the above equation, we get ok= one million/2 consequently, 2*z*x = y is the solutions. via ways, how previous are you??

Answer 4

hard thing. search from yahoo. that will could help!