i have two points in R3, p1(x1,y1,z1) and p2(x2,y2,z2).. y need the equation for this rect, for can arrive from p1 to p2 in a rect line, this is for rocket direccion. thank''s

Uhh, how about v = p2 - p1?
I''m sorry, I really don''t understand your question. But, if the rocket is supposed to go from p1 to p2, the direction of v, above, will the the direction the rocket needs to travel in order to reach p2.

You also need another point to show the plane in which that rocket will be flying. If you have only 2 points, then the line made from them is lying on infinite number of planes. E.g of your points are on 0X axis, then point 3 obviously should be lying in XZ or XY plane (depends what your gravity vector).

Cheer.s

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