The definition of Point-Slope Form is any equation of the form:
y-y¹ = m(x-x¹)
Note: There is no graphing. We seek the equation of the line.
ex) Find the equation through (3,-4) with slope m=1/2.
1) We “plug in” the numbers into our equation:
y – y¹ = m(x-x¹)
y-(-4) = ½(x-3)
2) This becomes our Point-Slope Form:
y+4 = ½(x-3)
2) Distribute and Isolate y:
y+4 = ½x – 3/2
3) This now becomes our Slope-Intercept Form:
y = ½x – 11/2