**Vectors in 3-D**

**Unit vector: **A vector of unit
length.

**Base vectors for a rectangular coordinate
system: **A set of three mutually orthogonal unit vectors

**Right handed system: **A coordinate
system represented by base vectors which follow the right-hand rule.

**Rectangular component of a Vector:**
The projections of vector ** A** along the

**Magnitude of a Vector:**

**Direction Cosines: Cos(****a), Cos(****b),
Cos(****g)**

**Unit vector along a vector: **The
unit vector __u___{A} along the vector ** A** is
obtained from

**Addition of vectors: **The resultant
vector __F___{R} obtained from the addition of vectors __F___{1},
__F___{2}, …, __F___{n} is given by

**Coordinates of points in space: **The
triplet (*x,y,z)* describes the coordinates of a point.

**The vector connecting two points: **The
vector connecting point *A *to point *B* is given by

**A unit vector along the line A-B:
**A unit vector along the line

**A vector along A-B:** A vector

**The dot product:** The dot product of
vectors ** A** and

**Projection of a vector by using the dot
product:** The projection of vector ** A** along the unit
vector

**Examples:**