SOLUTION: If the lines 4x-y+2=0 and x+2ky+1=0 are perpendicular to each other, determine the value of k

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Question 931563: If the lines 4x-y+2=0 and x+2ky+1=0 are perpendicular to each other, determine the value of k
Answer by tommyt3rd(5050) About Me  (Show Source):
You can put this solution on YOUR website!
For a line in the general form,
Ax%2BBy%2BC=0,
m=-A%2FB
so
m%5B1%5D=-4%2F%28-1%29=4
and
m%5B2%5D=-1%2F%282k%29
we require that
m%5B1%5Dm%5B2%5D=-1
therefore...
-4%2F%282k%29=-1
so

k=2