Slope Formula

Slope Formula

Poll

How did your Delta Math assignment go last night?

• Loved it! I'm all done!

• I tried but I got stuck so I stopped.

• I thought about it but didn't get to it.

• What is Delta Math again?

Slope: Review

• Rise/Run =

   $\frac{\Delta y}{\Delta x}$  

• Gives the rate of change

• Can be positive (walking uphill from left to right)

• Can be negative (walking downhill from left to right)

Finding the slope: Graphically

• Pick two points where the line intersects a corner on the grid

• Count the units for rise - going up/down (negative if going down)

• Count the units for run - ALWAYS TO THE RIGHT

• Simplify if necessary

Graphically

Find the slope

Poll

What is the slope of the line?

• 3

• 3/8

• 8/3

• -8/3

Slope Formula

Open Ended

What is one thing that you NOTICE about the slope formula? What is one thing that you WONDER about the slope formula?

Applying the Slope Formula

1) Write the slope formula

2) Label your coordinates as (x1, y1) and (x2, y2)

3) Substitute the coordinates into the slope formula

4) Subtract and simplify

Multiple Choice

Use the slope formula to find the slope of the line connecting the following coordinates.

(-4, 0) and (-4, -10)

• 0

• Undefined

• -10

• 5/2

Multiple Choice

Use the slope formula to find the slope of the line connecting the following coordinates.

(-9, 10) and (21, 15)

• 5/12

• -6

• 1/6

• 5/30