Question

What is the slope of the line, perpendicular to the line 3x - 6y = 4?

A) -2 B) 2 C) 2/3 D) -2/3

Answer 1

Note: If two lines are perpendicular to each other then their slopes are negative reciprocals

of each other.

let two lines have slope m1 and m2

then m2 = - 1/m1

=> m1 x m2 = -1

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Solution:

given, equation of first line = 3x-6y=4

=> (3x-4)/6=y

comparing this with y= mx + c we have slope of this line (m1) =3/6 = 1/2

let the slope of second line is (m2)

since the second line is perpendicular to the first line.

Therefore, (m1) x (m2) = -1

=> (1/2) x (m2) = -1

=> (m2) = - 2

Answer: (A) -2

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