Question 72994
Y=mX+b IS THE STANDARD LINE EQUATION FOR GRAPHING.
IF YOU HAVE TWO POINTS (2,-3)&(5,0) YOU CAN FIND THE SLOPE BY THE FORMULA
(Y2-Y1)/(X2-X1) THUS
(0+3)/(5-2)
3/3=1 WHICH IS THE SLOPE OF A LINE THROUGH THESE TWO POINTS.
NOW SUBSTITUTE ONE SET OF X,Y POINTS IN THE LINE EQUATION & SOLVE FOR THE Y INTERCEPT (b). THUS:
-3=1*2+b
-3=2+b
b=-3-2
b=-5 THUS THE FORMULA FOR THIS LINE IS:
Y=X-5
THE GRAPH OF THIS LINE FOLLOWS:
{{{ graph( 300, 200, -6, 5, -10, 10, y = x -5) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, y = x -5).