Slope and Direct Variation

Slope from 2 points

100

What is the slope between (3,5) and (4, 9)?

4

200

What is the slope between (3,5) and (-2, 9)?

4/-5

300

What is the slope between (0,2) and (-4, 2) 

0 

400

What is the slope of a vertical line?

Undefined 

500

Find the slope (7, 4) (12, 4) 

Zero

Direct Variation

100

Does this equation represent a direct variation? 

2x=y 

yes 

200

What is k? y=1/2x 

1/2 

300

Does the table represent a direct variation? 

x| 1     2     3     4 

______________________

y| -2    0     2     4 

no

400

What two things must be true for a graph to be a direct variation? 

Goes through the origin and is a straight line 

500

 The table shows a dirct variation between the cost in dollars (c) of potatos and the weight in pounds (p). Write an equation that shows the cost of potatos per pound.

P |    3      5      7      9

____________________

C |   15    25    35    45

c=5p

Slope from a Graph

100

Which direction(s) is rise? 

up or down 

200

Which direction(s) is run? 

left or right 

300

Draw an example of a graph with a negative slope 

\ 

400

Draw an example of a graph with a positive slope 

/ 

500

Draw an example of a graph with an undefined slope 

| 

Constant of Variation

100

what variable represents the constant in y=kx 

k 

200

What is the constant of variation of y = 8/11x

8/11

300

What is the constant of variation of the table 

x| 10    12   14   16

________________

y| 5      6     7     8 

1/2 

400

What is another name for the constant of variation?

Slope, unit rate 

500

What is the constant of variation in the equation? 

4y=5x 

4/5 

Mixed Bag

100

What kind of slope does a horizontal line have? 

zero slope 

200

What is the formula for finding slope? 

Y₂-Y₁

_{_______}

X₂-X₁

300

Find the slope (-6, 2) and (3, 4) 

2/9 

400

What is the direct variation equation?

y=kx

500

Find the slope (-13, 26) and (7, 2)

6/5