I'm trying to do something that looks quite simple to me, I have two set of points and I want to display the two lines passing through each of the set. for example if I have P1=(1,1) P2=(2,2) and P3=(-1,1), P4=(-2,2), I want wolfram to draw the lines y=x (as it pass through P1 and P2) and y=-x, how to do this?
there's no problem for one line, in fact if I type:
line [(1,2) (3,4)]
it shows the correct line along with the points, but I can't find a way to show two lines. I tried:
line [(1,2) (3,4)][(2,3)(4,5)]
line [(1,2) (3,4)] line [(2,3)(4,5)]
Graphics[Line[{{1, 0}, {2, 1}}], Line[{{3, 0}, {4, 1}}]]
Line[{{1, 0}, {2, 1}}, {{3, 0}, {4, 1}}]
how can I do it?