2.5 day 2: Family of lines Ex 6: a) Write the equation of the family of lines that are parallel to the line 5x +12y + 7 = 0.
b) Find the equations of the members of the family that are 3 units from the point (2,1).
Ex 7: The line 2x ­ 3y + 2 = 0 is midway between two parallel lines 6 units apart. Find the equations of the two lines.
The equation of the family of lines passing through the intersection of 2 given lines
Let the equations
A1x + B1y + C1 = 0
A2x + B2y + C2 = 0 define 2 intersecting lines. Then the equation
(A1x + B1y + C1) + k(A2x + B2y + C2) = 0
Ex 8: a) Write the equation of the family of lines that pass through the intersection of 2x ­ y ­ 1 = 0 and 3x + 2y ­12 = 0. b) Find the member of the family that passes through (­2, 1).