Hello,
I'm supposed to find the x and y values for two functions
so on my graph two trend lines intersect and I need to find the exact point at which they do so.
Is it possible to make it so that calc sets the two equations equal to each other then solves for a variable?
[Solved] Graphing Intersection of Trend Lines
[Solved] Graphing Intersection of Trend Lines
Last edited by MrProgrammer on Sat Dec 19, 2020 5:04 am, edited 1 time in total.
Reason: Tagged ✓ [Solved]
Reason: Tagged ✓ [Solved]
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Re: Graphing Intersection of Trend Lines
Say you have the formulas for the two trend lines in the form of...
ax+by=c
dx+ey=f
You could enter the constants into A1:C2...
A1=a B1=b C1=c
A2=d B2=e C2=f
Then in any other cell type an equals sign followed by...
MMULT(MINVERSE(A1:B2);C1:C2)
then press Ctrl+Shift+Enter to enter this array formula.
It's a multivalued array formula that returns two values. The top value is the x coordinate and the lower value is the y coordinate of the point of intersection.
If you are wondering why I didn't add the equals sign myself, it was to prevent you from copying the whole formula then pasting it into a cell. Array formulas can fail to work when transferred this way.
Ken Johnson
ax+by=c
dx+ey=f
You could enter the constants into A1:C2...
A1=a B1=b C1=c
A2=d B2=e C2=f
Then in any other cell type an equals sign followed by...
MMULT(MINVERSE(A1:B2);C1:C2)
then press Ctrl+Shift+Enter to enter this array formula.
It's a multivalued array formula that returns two values. The top value is the x coordinate and the lower value is the y coordinate of the point of intersection.
If you are wondering why I didn't add the equals sign myself, it was to prevent you from copying the whole formula then pasting it into a cell. Array formulas can fail to work when transferred this way.
Ken Johnson
AOO 4.1.3 on Ms Windows 10
Help improve this forum by clicking the EDIT button on your first post then adding "[Solved]" to its heading once a solution to your problem has been provided.
Help improve this forum by clicking the EDIT button on your first post then adding "[Solved]" to its heading once a solution to your problem has been provided.
Re: Graphing Intersection of Trend Lines
I know this is an old post and I'm probably doing the wrong thing reviving it, but my problem is similar except one line is horizontal.
Is it necessary to go through the whole array stuff ?
I have a line that starts at x=.01, y=18
and ends at x=.05, y=91
The horizontal line is y=75, with start and end x as above.
The vertical line I am hoping to get should intersect at around x=.04
Is it necessary to go through the whole array stuff ?
I have a line that starts at x=.01, y=18
and ends at x=.05, y=91
The horizontal line is y=75, with start and end x as above.
The vertical line I am hoping to get should intersect at around x=.04
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Re: Graphing Intersection of Trend Lines
=FORECAST(75;{0.01;0.05};{18;91})
Mr. Programmer
AOO 4.1.7 Build 9800, MacOS 13.6.3, iMac Intel. The locale for any menus or Calc formulas in my posts is English (USA).
AOO 4.1.7 Build 9800, MacOS 13.6.3, iMac Intel. The locale for any menus or Calc formulas in my posts is English (USA).
Re: Graphing Intersection of Trend Lines
Aahh! another formula I'd never heard of.
Too easy.
Thank you very much.
Too easy.
Thank you very much.
LibreOffice 5.1.4.2
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