What is the value of k such that the line through (-1, k) and (5, -2) is perpendicular to the line with equation y=3x+1?
a) 1/3
b) 0
c) -1/3
d) 3
*please please please explain why. Thanks a ton. :D
a) 1/3
b) 0
c) -1/3
d) 3
*please please please explain why. Thanks a ton. :D
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Perpendicular lines have slopes that are negative reciprocals of each other so the slope of the perpendicular line is -1/3.
(k - -2)/(-1 - 5) = -1/3
(k + 2)/-6 = -1/3
k + 2 = 2
k = 0
Answer is (b).
(k - -2)/(-1 - 5) = -1/3
(k + 2)/-6 = -1/3
k + 2 = 2
k = 0
Answer is (b).