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Plot[{4 - 2 y, (5 + y)/3}, {y, 1, 10}]

graph

How do I make Mathematica tell me the coordinates for cuts with the y-axis, other than just looking at it?

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Have a look at the documentation for Solve. –  Sjoerd C. de Vries Aug 24 at 19:32

2 Answers 2

up vote 3 down vote accepted

You can also use the MeshFunctions option to get the intercepts as follows:

Plot[{4 - 2 y, (5 + y)/3}, {y, -10, 10},
      MeshFunctions -> {#2 &}, Mesh -> {{0.}},  MeshStyle -> PointSize[Large]]

enter image description here

Plot[{4 - 2 y, (5 + y)/3}, {y, -10, 10},
      MeshFunctions -> {#1 &}, Mesh -> {{0.}},  MeshStyle -> PointSize[Large]]

enter image description here

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I'm a little bit disappointed that you got the acceptance :) –  eldo Aug 25 at 21:53
    
@eldo, i know the feeling :) –  kguler Aug 25 at 22:02
fun = {4 - 2 y, (5 + y) / 3};

p = Flatten @ Map[Solve[# == 0, y] &, fun] /. Rule[_, a_] :> a

{2, -5}

Plot[fun, {y, -10, 10},
 Epilog -> {PointSize@0.02, Point[{#, 0}] & /@ p},
 FrameTicks -> {p, Automatic},
 FrameTicksStyle -> 12,
 GridLines -> {p, {0}},
 ImageSize -> 500,
 PlotTheme -> "Detailed"]

enter image description here

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