Question 18407: example...
2x>0
when you graph the equation and x isnt greater than 0...where do i shade?
the shading confuses me. please help!!!
Answer by josmiceli(19441)   (Show Source):
You can put this solution on YOUR website! When you think about the x-axis, just imagine that y=0. Of course, y can be
anything if you are only talking about the x-axis, which is horizontal.
With y=0, you are always on the x-axis itself.
There are only (3) things that x can be:
(1) negative
(2) zero
(3) positive
So now you're on the x-axis, and you wan to know where 2x > 0 exists and where
it doesn't exist. You know (or should know) that zero divided by anything
except zero is still zero.
x > 0/2 --divide both sides of inequality by 2
x > 0 --what I said last paragraph
Look at the three things that x can be. The only one that fits x > 0 is
(3) positive. Now the trick is to let y be anything it wants to be. That
means zero, negative, or positive. Your solution is that x can be anywhere
in the 1st and 4th quadrants, letting y roam free.
2nd|1st
---+---
3rd|4th
Remember that x can't be zero, that would mean x = 0, not x > 0.
Do you want to shade everywhere that you don't find a solution to
x > 0 ? Then you must shade the 2nd and 3rd quadrants and also
shade the y-axis- because the y-axis is where x=0 and y can roam free.
Hope this helps. I've gotten confused numerous times, too, and the
best advice I have is to give it the effort it requires until you're
confident. Good luck.
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