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How to draw the function x+5<7

  1. Aug 12, 2013 #1
    I am just interested in knowing, how to draw the function x+5<7 in a cartesian plane.
    Since the definition of a function is, If For a certain input, there exist an out, then it is a function.
    Is x+5<7 is a valid function then?
  2. jcsd
  3. Aug 12, 2013 #2
    What you wrote is an inequality, not a function.
  4. Aug 12, 2013 #3
    If the inequality has only one variable (as yours does), you would graph the solution on a number line. If the inequality has two variables (x and y), then you could graph the solution on a Cartesian plane.
  5. Aug 15, 2013 #4


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    To draw a graph of this inequality, first draw the graph of the corresponding equation. x+ 5= 7. That. of course, is the same as "x= 2". It's graph, in a two dimensional "xy" graph, is the vertical line at x= 2. The set of points for which x+ 5< 7 is the set of points for which x< 2. That is, all points to the left of that vertical line.
  6. Aug 16, 2013 #5
    But if we take y=(x+5) and then, draw the graph, wouldn't it give different results??
  7. Aug 17, 2013 #6


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    Of the simple reason that the first inequality does not place any sort of restrictions on the y-coordinate in the points' (x,y) coordinate pairs.
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