1. PARALLEL AND PERPENDICULAR LINES ALGEBRA 2/GEOMETRY HIGH SCHOOL

2. PARALLEL LINES MAP TAP 2003-2004 Parallel and Perpendicular Lines2 Two non-vertical lines are parallel if and only if their slopes are equal. If l 1 ║ l 2, then m 1 = m 2. If m 1 = m 2, then l 1 ║ l 2. l1l1 l2l2 m1m1 m2m2

3. WRITE THE EQUATION OF THE LINE THAT PASSES THROUGH (3,6) AND IS PARALLEL TO Y = 2 X+2 3 m = 2/3 and the point is (3,6) y = mx+b 6 = 2/3(3)+b 6 = 2+b 4 = b y = 2/3x+4 MAP TAP 2003-2004 Parallel and Perpendicular Lines 3

4. WRITE THE EQUATION OF THE LINE THAT PASSES THROUGH (4,-5) AND IS PARALLEL TO Y = -2X-4. m = -2 and the point is (4,-5) y = mx+b -5 = -2(4)+b -5 = -8+b 3 = b y = -2x+3 MAP TAP 2003-2004 Parallel and Perpendicular Lines4

5. WRITE THE EQUATION OF THE LINE THAT PASSES THROUGH (- 6,4) AND IS PARALLEL TO Y= 1 X-1 3 m=1/3 and the point s (-6,4) y =1/3x+6 MAP TAP 2003-2004 Parallel and Perpendicular Lines5

6. PERPENDICULAR LINES Parallel and Perpendicular Lines6 Two non-vertical lines are perpendicular if and only if the product of their slopes is -1. If l 1 ┴ l 2, then m 1 ● m 2 = -1. If m 1 ● m 2 = -1, then l 1 ┴ l 2. l1l1 l2l2 m2m2 m1m1 Slopes are negative reciprocals

7. WRITE THE EQUATION OF THE LINE THAT PASSES THROUGH (6,-5) AND IS PERPENDICULAR TO Y = 2X+3. m = -1/2 and the point is (6,-5) y = mx+b -5 = -1/2(6)+b -5 = -3+b -2 = b y = -1 x-2 2 MAP TAP 2003-2004 Parallel and Perpendicular Lines7

8. WRITE THE EQUATION OF THE LINE THAT PASSES THROUGH (6,-7) AND IS PERPENDICULAR TO Y = 2/3X+1. m = -3/2 and the point is (6,-7) y = mx+b -7 = -3/2(6)+b -7 = -9+b 2 = b y = -3 x+2 2 MAP TAP 2003-2004 Parallel and Perpendicular Lines8

9. WRITE THE EQUATION OF THE LINE THAT PASSES THROUGH (-4,-3) AND IS PERPENDICULAR TO Y = X+6. m = -1 and the point is (-4,-3) y = -x-7 MAP TAP 2003-2004 Parallel and Perpendicular Lines9