Answer:
What is a reasonable domain for the two functions?
x > 0
The second line of eauation y=-2x+5 is parallel to a since both have the same slope which is -
-2
the first line of equation y=2x-1 is neither perpendicular nor parallel to a since the (slope of this line) x (the slope of a) = 2 x -2 = -4 not -1, so they aren't perpendicular and its slope isn't equal to that of a, so they aren't parallel
the last line of equation y=1/2x+7 is perpendicular to a since (the slope of a) x (the slope of this line) = -2 x 1/2 = -1
