Vectors

PrintPrint
  Content Further guidance Links
4.1

Concept of a vector.

Representation of vectors using directed line segments.

Unit vectors; base vectors i, j, k.

Components of a vector:

Algebraic and geometric approaches to the following:

the sum and difference of two vectors;

the zero vectors 0 , the vector −v ;

multiplication by a scalar, kv ;

magnitude of a vector, |v| ;

position vectors

Proofs of geometrical properties using vectors. Distance between points A and B is themagnitude of
  • Aim 8: Vectors are used to solve many problems in position location. This can be used to save a lost sailor or destroy a building with a laser-guided bomb.
  • Appl: Physics SL/HL 1.3 (vectors and scalars); Physics SL/HL 2.2 (forces and dynamics).
  • TOK: Mathematics and knowledge claims. You can perform some proofs using different mathematical concepts. What does this tell us about mathematical knowledge?
4.2

The definition of the scalar product of two vectors. Properties of the scalar product:

The angle between two vectors. Perpendicular vectors; parallel vectors.

Link to 3.6.

For non-zero vectors, v ⋅ w = 0 is equivalent to the vectors being perpendicular.

For parallel vectors, |v ⋅w| = |v| |w| .

  • Appl: Physics SL/HL 2.2 (forces and dynamics).
  • TOK: The nature of mathematics. Why this definition of scalar product?
4.3 Vector equation of a line in two and three dimensions: r = a+ λb . Simple applications to kinematics.The angle between two lines.

Knowledge of the following forms for equations of lines.

Parametric form:

  • Appl: Modelling linear motion in three dimensions.
  • Appl: Navigational devices, eg GPS.
  • TOK: The nature of mathematics. Why might it be argued that vector representation of lines
4.4 Coincident, parallel, intersecting and skew lines; distinguishing between these cases. Points of intersection. . .
4.5

The definition of the vector product of two vectors.

Properties of the vector product:

Geometric interpretation of |v × w| .

v × w = |v| |w| sinθ n , where θ is the angle between v and w and n is the unit normal vector whose direction is given by the right- hand screw rule. Areas of triangles and parallelograms.
  • Appl: Physics SL/HL 6.3 (magnetic force and field).
4.6

Vector equation of a plane r = a +λb + μc .

Use of normal vector to obtain the form r ⋅ n = a ⋅ n.

Cartesian equation of a plane ax + by + cz = d .

. .
4.7

Intersections of: a line with a plane; two planes; three planes.

Angle between: a line and a plane; two planes.

Link to 1.9.Geometrical interpretation of solutions.
  • TOK: Mathematics and the knower. Why are symbolic representations of three-dimensional objects easier to deal with than visual representations? What does this tell us about our knowledge of mathematics in other dimensions?

Previous page | Next page