What two pieces of information do you need to write an equatuon in point-slope form?

You need an point (x, y) that lies on the graph, and you need the slope of the line.

Step-by-step explanation:

The formula for point-slope form is:

  y - y1 = m(x - x1)       where m is the slope, and (x1, y1) is a point on the graph

Finding the point (x,y):

  This is is usually given in the problem you are asked, and you can plug that point in to the formula above.

 Ex:  A line with a slope of 3 passes through the point (1, 4).  Write the equation for this line using point-slope form.

     The slope is 3, the point given is (1, 4).  So using point-slope form,        we get

                 y - 4 = 3(x - 1)

the distance between point a and point b is 6 units