Mathematics - PearsonAccess.com

Objective 7Which line graphed below is perpendicular to the line y 1 x 5?2ay987654321–9 –8 –7 –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 6 7 8 9–1–2–3–4–5–6–7–8–9xb987654321–9 –8 –7 –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 6 7 8 9–1–2–3–4–5–6–7–8–9xFind the slope of the line y 1 x 5. The equation is in the2form y mx b; therefore, its slope, m, is 1 2 .Which graph has a slope equal to the negative reciprocal of 1 2 ?The negative reciprocal of 1 2 is 2 , or 2.1Line aLine bPick any two points onthe graph.(0, 5), (4, 3) (0, 5), (2, 1)Find the change in y 2 y 1 3 5 y 2 y 1 1 5y-values, or the rise. y 2 y 1 8 y 2 y 1 4Find the change in x 2 x 1 4 0 x 2 x 1 2 0x-values, or the run. x 2 x 1 4 x 2 x 1 2Write the slope as the ratioof rise to run. 8 24 42 4 2 2yLine a has a slope of 2, so line a is perpendicular to the liney 1 x 5.2180