4.2 POINT-SLOPE
FORM OF A LINE
Point-Slope form:
 y  y1   mx  x1 
( x1 , y1 )  any point on the line
m  slope
Ex 1: Write the equation of the
line that passes through the given
point and has the given slope.
(7,3)
a) Slope = 2
b) Slope = 
3
5
( 4,2)
Ex 2: Write the equation of the
line that passes through the given
points.
a)
( 4,3) & (2,3)
b)
(1,3) & (0,8)
The SLOPE Formula:
y y  y1
m 
x x2  x1
) a n d ( x 2 , y 2 ) is :
2
HW – 4.2 PG. 227
#11 – 21 ODDS,
22, 24, 25-29 ODDS
(11 PROBLEMS)
•HORIZONTAL LINES:
•SLOPE = M = 0
•Y-INTERCEPT (0, B)
•VERTICAL LINES:
•SLOPE = M IS UNDEFINED
•NO Y-INTERCEPT