Question 1056091
Find the distance between the given two lines.  y=-x+4; y=-x
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Pick a point on y = -x.  (0,0) is good.
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The distance from a point (x,y) to a line ax + by + c = 0 is
|ax + by + c|/(sqrt(a^2 + b^2)
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y=-x+4 --> x + y - 4 = 0
d = |-4|/sqrt(1 + 1) = 4/sqrt(2)
d = 2sqrt(2)