Geogebra help wtih lines in 3D

Question

I'm trying to plot the lines $x=(y-5)/3=(z+3)/2, x=(y-7)/4=(z-10)/5$ on Geogebra but it doesn't seem to plot anything. What am I doing wrong here? I'm also using the form Line[point,direction vector], but Geogebra seems to take the direction vector as a point instead and it calculates a new direction vector $v=(1,-2,5).$ How can I fix this?

Answer 1

Functions in GeoGebra are polymorphic, so you need to be careful to have the right types of arguments, especially when there are alternative forms of the function with the same number of arguments. In particular, there are two similar-looking forms of the Line function: Line[Point, Point] and Line[Point, Vector]. GeoGebra reads an ordered triple as a point, so the input Line[(0,5,-3), (1,3,2)] is interpreted as the former form of the function. In some situations, GeoGebra will silently coerce a point into a vector, but because of the ambiguity between these two forms of Line it doesn’t, so you have to turn the second argument into a vector explicitly: Line[(0,5,-3), Vector[(1,3,2)]].