# Movable axes crossing curve

lineup shared this question 6 years ago

The enclosed worksheet shows movable axes centered in A, default coords (4,2), which cross two 'green' segments not so far from (2,6) and (-2,4).

Is it possible to determine accurate intersections? Which input command should be given?

li

https://ggbm.at/568453

1

Hi,

Intera=intersection with vertical axis :

Intera=Element[RemoveUndefined[Sequence[Intersect[Element[list4, i], a], i, 1, Length[list4]]], 2]

Intera=intersection with horizontal axis :

Interb=Element[RemoveUndefined[Sequence[Intersect[Element[list4, i], b], i, 1, Length[list4]]], 1]

just an undecided choice from point of intersection...(Element n°1 or n°2 ???)

with RemoveUndefined[Sequence[Intersect[Element[list4, i], b], i, 1, Length[list4]]]

we have the list of intersections

https://ggbm.at/568455

1

Thank you, it is a good solution.

In addition, please, is it possible to solve the included intersection with hyperbola on moving point D? Default D=(8,8), n=50. Thanks

li

https://ggbm.at/568459

1

Hi,

Currently the Intersect[] command is more powerful in CAS than in the algebra-window.

• Define the objects in the algebra-windows

Write the Intersect[] command in CAS in a free cell (without or with CAS-cell-name)

Click in CAS to the radio-button on the left side in the CAS-cell with the Intersect[]-command

And here the solution with approximation (without CAS)

.

Raymond

1

Satisfactory (B) solution. Please see the included worksheet, thank you very much and best regards

li

https://ggbm.at/568479

1

Condition to show object (see included file).

Please, I need to delete "ellip" when "hyper" is selected. Thank you

li

https://ggbm.at/568487

1

Hi

ellip is the 3. Element of the list "show".

so the object sel_I has the value 3 when ellip is selected in the graphic view

Set for all object there are show only if ellip is selected sel_I==3 in Condition to show object

as follow:

mark this objects in the algebra view with press ctrl (B,C,D,list8, ellip)

right-click (of one of this marked objects) / object-properties / advanced

in the top (Condition to show object) write sel_I==3 / enter

Raymond

https://ggbm.at/568489

1

Understood now: sel_I [question mark over equal mark] means sel_I==

Thank you and best regards

li

1

New feature: how to compute the marked area between line and polygon?

li

1
1

Good solution, better if the closed area be filled moving the line up to y=2x-18.

Thank you

li

1

Solved. Thank you and best regards

li