Author Topic: Trying to Graph basic equations on an nspire cx... (Read 5002 times)

cnwinger · « **on:** December 02, 2015, 09:13:41 pm »

I read the manual which tells me to choose:

Menu -> Graph Entry -> Equation -> Line

the problem is that 3 Line types available to choose all want to auto-fill in parts of the equation, which I cannot go back and edit. I don't see any possible way to enter the following:

2x – 3y + 12 = 0

What am I missing here?

Thanks…

Ivoah · « **Reply #1 on:** December 02, 2015, 09:59:24 pm »

Quote from: cnwinger on December 02, 2015, 09:13:41 pm

I read the manual which tells me to choose:

Menu -> Graph Entry -> Equation -> Line

the problem is that 3 Line types available to choose all want to auto-fill in parts of the equation, which I cannot go back and edit. I don't see any possible way to enter the following:

2x – 3y + 12 = 0

What am I missing here?

Thanks…

You can use simple algebra to rearrange it into something the Nspire can handle

2x - 3y + 12 = 0
2x + 12 = 3y
3y = 2x + 12
y = (2x + 12)/3
y = x*(2/3) + 4

cnwinger · « **Reply #2 on:** December 02, 2015, 10:23:44 pm »

Oh, I assumed the nsprie could handle that. Thanks for the clarification.

So that is simple enough to get it down to that point (solve for Y)..but what are the steps to then enter that into the graph? I'm not sure which option to use.

I tried the function, but it only seems to want the X value.

Ivoah · « **Reply #3 on:** December 02, 2015, 10:26:32 pm »

You want to use the function graphing.

The final input should look something like this: f1(x)= x*(2/3) + 4

cnwinger · « **Reply #4 on:** December 02, 2015, 10:47:04 pm »

now I see. Thanks for your help!

cnwinger · « **Reply #5 on:** December 02, 2015, 11:20:37 pm »

One more thing that is escaping me...isn't there a way to auto-display the x and y intercepts on a straight line?

I see I can get it to display the X intercept manually using the "zero" action. I don't know how to get the Y intercept.

Ivoah · « **Reply #6 on:** December 05, 2015, 08:46:25 pm »

Quote from: cnwinger on December 02, 2015, 11:20:37 pm

One more thing that is escaping me...isn't there a way to auto-display the x and y intercepts on a straight line?

I see I can get it to display the X intercept manually using the "zero" action. I don't know how to get the Y intercept.

You can find the y intercept of any equation by just replacing the x with 0 and solving for y, which in this case the equation is already solved for y.

Author Topic: Trying to Graph basic equations on an nspire cx... (Read 5002 times)

cnwinger

Trying to Graph basic equations on an nspire cx...

Ivoah

Re: Trying to Graph basic equations on an nspire cx...

cnwinger

Re: Trying to Graph basic equations on an nspire cx...

Ivoah

Re: Trying to Graph basic equations on an nspire cx...

cnwinger

Re: Trying to Graph basic equations on an nspire cx...

cnwinger

Re: Trying to Graph basic equations on an nspire cx...

Ivoah

Re: Trying to Graph basic equations on an nspire cx...