# How to intersect a Curve and a Line?

Swulf shared this question 9 years ago

Hello,

I am unable to intersect the rotated Curve 'aa' and the Line 'e'. :( I would like Points to be available at the intersections.

Can it be done?

Thanks,

Swulf

https://ggbm.at/553207

1

Hi

The curve command doesn't create an object which has an "intersection property" with another curve or equation. You might have to work out the intersection points yourself and put them on separately.

You could move this request to the GeoGebra forum proper for other ideas.

Why there are two forums I don't know..

regards

Paul

1

Hi,

It's a shame that feature is not supported as it seems very useful and necessary.

Swulf

1

Hi Swulf,

As a workaround try creating a point with these co-ordinates:

(0,sin(rotation°) r(pi/2-rotation°) cos(pi/2-rotation°) +cos(rotation°) r(pi/2-rotation°) sin(pi/2-rotation°))

It will move up and down with the rotating curve.

M_OLoughlin

1

Hi

One workaround more in the annex

Raymond

https://ggbm.at/553235

1

hello

Your request is equivalent to solving any system of equations. i think this is not possible.

in this case you can use

aa=Curva[r(t) cos(t + rotation°), r(t) sin(t + rotation°), t, 0, 6.28319]

C=(0, r(90° - rotation°))

it is similar Raymon's method but shorter (you can delete "a" or modify r(x) )

saludos

1

Intersect[ <Line>, <Curve> ] works from 4.1.108.0