Find the constant
Write Direct Variation Equation Given y and x
Given Direct Variation Equation, Find x or y
Is it Direct?
Questions/Definitions
100
y=3x What is the constant of variation?
3
100
y=6 and x=3. Write the direct variation equation.
y=2x
100
If y=2x and x=4, what is y?
8
100
Is the following a direct variation function?
y=5x
yes
100
Can you have addition or subtraction in a direct variation equation?
no
200
y= 1/2 x
What is the constant of variation?
1/2
200
y=42 and x=6. Write the direct variation equation.
y=7x
200
If y=.3x and x=10, what is y?
3
200
Is the following a direct variation function? y= 4x+3
no
200
Can you have division in a direct variation equation?
yes
300
y=4, and x=2 What is the constant of variation?
2
300
y=256 and x=4. Write the direct variation equation.
y=64x
300
If y=4x and y=8, what is x?
2
300
Is the following a direct variation function? y= -5x
yes
300
How can you tell if something is a direct variation simply by looking at a picture of a graph? (Name the two things you're looking for)
it's a straight line and it crosses through (0,0)
400
y=100, and x=5 What is the constant of variation?
20
400
y=500 and x=25. Write the direct variation equation.
y=20x
400
If y=.5x and y=6, what is x?
12
400
Is the following a direct variation function? .56y = 4738x
yes
400
In a distance over time graph, what does a horizontal line represent?
being stopped
500
y=3, and x=12 What is the constant of variation?
1/4
500
y=1/4 and x=1/8. Write the direct variation equation.
y=2x
500
If y=(1/3)x and y=3, what is x?
9
500
Is the following a direct variation function? y=x/3
yes
500
In a speed over time graph, what does a horizontal line represent?
speed is constant