1. Finding the Equation of a Line Using Point Slope Formula

2. What is the Point Slope Formula?
When given a point and a slope of a line or two points of a line, the point slope formula allows you to find the equation of that line.
The equation that you find will be in the form of

3. What Does It Look Like? The formula takes the form of:
Where m= slope of the line and
and are the point coordinates

4. Example 1
Find the equation of a line that has a slope of 2 and passes through the point (2,-4).
SO..
m=2, and
Now plug it in!!

5. ALWAYS CHECK YOUR ANSWER!!
Example 1 Continued
Recall:
Plugging in our values of m, and gives us:
Distribute the 2
Subtracting 4 to both sides gives us our answer
ALWAYS CHECK YOUR ANSWER!!

6. Example 1 Check Our answer was: Plug in our given point:
Simplify the right side:
GREAT JOB!

7. Example 2
Find the equation of the line that passes through the points (-1,5) and (2,6)
Recall:

8. Example 2 Continued
First find the slope (m) by plugging the two points into the slope formula.
Simplifying gives us:
Now we have and choosing one of the points given also gives us and
Now plug it in!!!

9. ALWAYS CHECK YOUR ANSWER!!
Example 2 Continued
Plug in the values of m
and
Distribute the
Adding the 6 to both sides gives us the answer
ALWAYS CHECK YOUR ANSWER!!

10. Example 2 Check Our answer was: Plug in the first point:
We’re not done yet!

11. Example 2 Check Continued
Our answer was:
Now plug in our second point:
GREAT JOB!