Lines a and b are perpendicular, the slope of line a is given below. What is the slope of line b? (A) 3 (B) 3/4 (C) -2 (D) -5/2 (E) -1/2 (F) 2/5 (G) 1

1 Answer
Jun 20, 2018

A) -1/313

B) -4/343

C) 1/212

D) 2/525

E) 22

F) 5/252

G) -11

Explanation:

The slopes of 2 perpendicular lines are related in that:
m_1 * m_2 = -1m1m2=1

So, if you know one slope, m_1m1, then the other slope, m_2m2, is the negative reciprocal of m_1m1:
m_2 = -1/m_1m2=1m1

A) If m_1 = 3m1=3, then: m_2 = -1/3m2=13
B) If m_1 = 3/4m1=34, then: m_2 = -4/3m2=43
C) If m_1 = -2m1=2, then: m_2 = 1/2m2=12
D) If m_1 = -5/2m1=52, then: m_2 = 2/5m2=25
E) If m_1 = -1/2m1=12, then: m_2 = 2m2=2
F) If m_1 = 2/5m1=25, then: m_2 = 5/2m2=52
G) If m_1 = 1m1=1, then: m_2 = -1m2=1