Graphing calculators...could someone help me with inequalities?

[Gamom3]

Ds is graphing inequalities, which he is to have shaded with the calculator.

Well on the Chalkdust video they show us but we are lost when we get to the book...since it isn't the same.

 

He is told this process 2nd,program, #7 type in the equation and then press enter.

 

Here is the problem y>/= 2x+1 y is greater than or equal to 2x+1

 

Well there is no number to put in for the shading..we typed in (2x+1),10--have no idea where this number comes from and it is right.

 

Next we do y</=-2x+4.

We type in (-2x+4),10 this is not right

 

So we go on to 6x+10y-15</=0 we change this to y</=-3/5x+3/2

so we type in (-3/5x+3/2), 10--again we are not sure where 10 comes from...still not right.

 

Could someone explain to me what I type in after the equation, since it is not aways 10?

[KAR120C]

It sounds like you're using the "shade" function (in the drawing menu?) to do the work, when I think it would be more straightforward to do it in the Y= screen where you normally enter graph equations. If you hit Y= and enter your equation, then you can arrow over to the left (past the Y to where there's a slash) and hit enter to change the slash (indicating a line graph) to a triangle. The triangle at the top is "greater than" and the triangle at the bottom is "less than". There are some other options there too, but those are the ones you're looking for.

 

Hope this helps!

Edited January 13, 2010 by KAR120C

[Gamom3]

I don't know why they taught it a different way than that. I am sure we will get to that eventually. Ds didn't even have one question that was to be done like it was showed on the video:angry: