







The line of intersection of two planes 
20151209 

Rabz pose la question : Determine the vector equation for the intersection between the two given planes
2x+7y equal to 14,x+z equal to 7 Penny Nom lui répond. 





The distance from a point to a line in 3 space 
20061029 

Marie pose la question : find the distance from the point (1, 2, 3) to the line x = y = z2 Penny Nom lui répond. 





Vectors in three space 
20041030 

Jo pose la question : I have two questions that I just cannot visulise and dont know how to get started on them..!
1. Ship X is sailing North at 4m/s and Ship Y is sailing due East at 3m/s. A sailor on Ship X climbs a vertical pole at 1/2 m/s. What is the velocity of the sailor on Ship X relative to an observer on Ship Y? State it's magnitude and direction.
Not sure where to start with this one...
2. Show, using vectors, that for any tetrahedron, the segments joining the midpoints of the opposite edges are concurrent.
i know what a tetradedron is, and what I am proving but do I solve simultaneously for a specific case?? Walter Whiteley lui répond. 





A cone in 3 space 
20020320 

Matthew pose la question : Let C in R^{3} be the cone defined by x^{2} + y^{2}  z^{2} = 0 (A) Let P be the plane described by x + 2z = 1 (i) Find a description of P in terms of two parameters s and t . . . Walter Whiteley lui répond. 





A set of points in space 
20020318 

Victoria pose la question : Describe the given set with a single equation or a pair of equations: The set of points in space that lie 2 units from the point(0,0,1) and at the same time 2 units from the point (0,0,1). Penny Nom lui répond. 





A line in 3 dimensions 
20011017 

Murray pose la question : I'm working on a complicated proof and i need the equation for a line in 3 dimensions. Claude Tardif lui répond. 





Intersection of planes 
19981122 

Dave Rasmussen pose la question : I am a teacher of secondary mathematics with a question about the uses of Three Dimensional Coordinate Geometry. I have been teaching my students to write equations of planes and lines,  to find the intersection of these and the distance between them. What I am having difficulty finding are good applications of these techniques to "real world" situations. Can anybody help me? Walter Whiteley and Harley Weston lui répond. 

