Dot product Dot product and orthonormal basis. Call the three axes x,y,z. O. Take i , j , k as unit vectors along the positive axes x,y,z. With each point P, corresponds a vector O P .
P is called the image point of O P .
The vector O P is noted P for short. The vector P can be expressed as x. A and B are two points in space. We have the same result starting from the center of another triangle. Lines Equations of a line in space Take a line BC in space.