SOLUTION: I'm supposed to choose between true or false for this statement. a line with a slope of zero is parallel to the x-axis, and a line with an undefined slope is parallel to the y-axis

Algebra ->  Coordinate-system -> SOLUTION: I'm supposed to choose between true or false for this statement. a line with a slope of zero is parallel to the x-axis, and a line with an undefined slope is parallel to the y-axis      Log On


   

Question 122459: I'm supposed to choose between true or false for this statement. a line with a slope of zero is parallel to the x-axis, and a line with an undefined slope is parallel to the y-axis. i think it's false, but am i right? if not then tell me that it's true. Thank you for your time.
Answer by tutor_paul(519) About Me  (Show Source):
You can put this solution on YOUR website!
The statement is TRUE. The definition of the slope of a line is:
slope=rise%2Frun
This is the same as:
slope=change_in_y%2Fchange_in_x
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If a line is running parallel to the x axis, the x value is changing but the change in y values is zero. So for a line parallel to the x axis,
slope=0%2Fchange_in_x
So the slope equates to zero.
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If a line is running parallel to the y axis, the y value is changing, but the change is x values is zero. So for a line parallel to the y axis,
slope=change_in_y%2F0
Having a zero denominator means this expression is undefined, so this line has no slope.
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Good Luck,
tutor_paul@yahoo.com