Point-Slope Formula

• Use Point-Slope Formula if you know the coordinates of one point and the slope of the line

*Hint: to find slope (m), use…m=

·      

y-y1=m(x-x1)

Once you find the slope (or if it is given), PLUG IN the point using:

Example problem

Use the Point-Slope Formula to find an equation of the line that passes through the point (2, 3) and has a slope of 3.

                (Hint: use 2 for x₁ and 3 for y₁)

        y-y₁=m(x-x₁)

ü    Plug in #s:  y-3=3(x-2)

ü    Get rid of parentheses by distributing:  y-3=3x-6

ü    Get “y” by itself (add 3 to both sides):  y=3x-6+3

ü    Simplify: