| Author | Comment |
campsoup1988
Probe
Posted: 12 May 2007
15:22 GMT
Total Posts: 7 | I am look for some advice on how to find the intersecton of two nonlinuar scatter plot xylines on my TI-83+ calc!
Thanks,
Campsoup1988
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No Comments...Wait That's a Comment Everyone is krazy...To some extent! |
haveacalc
Guardian
Posted: 12 May 2007
15:40 GMT
Total Posts: 1111 | You need four points (to get two equations). If you know what substitution or elimination are, that's what you do. If not, tell me more.
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-quoted directly from most movies that don't exist (and some that do). |
Zachary940
Wraith
Posted: 12 May 2007
15:45 GMT
Total Posts: 714 | Read your mannual. It will tell you how to make a nonlinear equation of a scatter plot. Put it in to y= and graph it. You can then graph bith eqations and use the command intersect (Found under the calc menu).
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It is much easier to suggest solutions when you know nothing about the problem. |
haveacalc
Guardian
Posted: 12 May 2007
15:49 GMT
Total Posts: 1111 | Lol, you don't need your calc. Avoiding easy things like intersection-finding is just laziness if you can't do it by hand. Also, your post count=7^3 :)
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-quoted directly from most movies that don't exist (and some that do). |
campsoup1988
Probe
Posted: 12 May 2007
15:50 GMT
Total Posts: 7 | haveacalc: I needed to make a line with more then 2 point per equation because the curve is not consistent (this is for an economic program)
Zachary940: I tried my manuel and all i could find is LinReg but it does not give me an option to choose which lists I want to use.
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No Comments...Wait That's a Comment Everyone is krazy...To some extent! |
haveacalc
Guardian
Posted: 12 May 2007
15:53 GMT
Total Posts: 1111 | Find a slope between the two pairs of points you want to find the intersection of. Then, go to [2ND], [TRACE] (topmost second-to-rightmost button), 5.intersect (like Zachary said) and find it (after you've graphed both slopes with the correct Y-intercepts). Do this for each intersection.
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-quoted directly from most movies that don't exist (and some that do). |
campsoup1988
Probe
Posted: 12 May 2007
15:56 GMT
Total Posts: 7 | the problem with that I need to incorperate more then 2 points because the slope could be like the following pic: http://www.adf.com.au/attachments/library/1997/competition_kilham_files/graph_1.gif
PS: I know the basic intersect command that you explained
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No Comments...Wait That's a Comment Everyone is krazy...To some extent! |
haveacalc
Guardian
Posted: 12 May 2007
15:58 GMT
Total Posts: 1111 | Is (delta)X (the value by which X increases) consistent between scatter plots?
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-quoted directly from most movies that don't exist (and some that do). |
campsoup1988
Probe
Posted: 12 May 2007
16:02 GMT
Total Posts: 7 | Im not exactly sure what you mean. Are you asking if they points follow a pattern? If that the question you are asking, then the answer is not always.
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No Comments...Wait That's a Comment Everyone is krazy...To some extent! |
haveacalc
Guardian
Posted: 12 May 2007
16:07 GMT
Total Posts: 1111 | If (delta)X is consistent, you get something like this for two scatter plots:
(1,3) (3,8) (5,4) (7,15)
and
(1,6) (3,2) (5,9) (7,5.5)
The X values line up exactly.
Just in case, here's a set that wouldn't line up exactly and would require more calculation:
(0,3) (3,6) (6,2) (9,9)
and
(2,13) (7,8) (12,5) (17,6)
Which are you working with?
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-quoted directly from most movies that don't exist (and some that do). |
campsoup1988
Probe
Posted: 12 May 2007
16:12 GMT
Total Posts: 7 | most likely the are consistent, but they are not always consistent though
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No Comments...Wait That's a Comment Everyone is krazy...To some extent! |
haveacalc
Guardian
Posted: 12 May 2007
16:13 GMT
Total Posts: 1111 | Could I have a sample problem?
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-quoted directly from most movies that don't exist (and some that do). |
campsoup1988
Probe
Posted: 12 May 2007
16:32 GMT
Total Posts: 7 | ok I just pulled a random graph out of my book:
line 1: (5,2), (4,4), (2,11), (1,16)
line 2: (1,1), (2,4), (4,10), (5,12)
Intersection:(3,7)
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No Comments...Wait That's a Comment Everyone is krazy...To some extent! |
haveacalc
Guardian
Posted: 12 May 2007
17:22 GMT
Total Posts: 1111 | I. Find the slope of the two points on each line that contain the intersection:
1. (4-11)/(4-2)=-3.5
2. (10-4)/(4-2)=3
II. Get the equations
1. If 4=-3.5(2)+B, B=18, equation is Y=-3.5X+18
2. If 11=3(2)+B, B=-2. equation is Y=3X-2
III. Solve
The Y values will be the same at the intersection, right? So:
-3.5X+18=3X-2
X=(20/6.5),Y=18-(70/6.5)
Intersection=(3.077,7.231)
Then, do the same for the other intersections. Was that all of it?
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-quoted directly from most movies that don't exist (and some that do). |
Zachary940
Wraith
Posted: 12 May 2007
17:26 GMT
Total Posts: 714 | @haveacalc: Yes I know you can do it by hand, and I do when I have too. But I'm just lazy. If I can use my calc I do.
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It is much easier to suggest solutions when you know nothing about the problem. |
haveacalc
Guardian
Posted: 12 May 2007
17:39 GMT
Total Posts: 1111 | Ok, posted.
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-quoted directly from most movies that don't exist (and some that do). |
campsoup1988
Probe
Posted: 12 May 2007
18:57 GMT
Total Posts: 7 | haveacalc that works if you know which segments are intersecting in. but if you are not looking a graph of already, you might not know which segments to use
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haveacalc
Guardian
Posted: 12 May 2007
19:33 GMT
Total Posts: 1111 | Well, if the point of intersection isn't within the bounds of the two points (or is nonexistent)...
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-quoted directly from most movies that don't exist (and some that do). |
