Vector Tests and Essential Skills

Vector Tests and Essential Skills

Parallel vectors and collinear points

\[\mathbf a\parallel\mathbf b\iff \mathbf a=\lambda\mathbf b\ \text{for some scalar}\hspace{0.5em}\lambda\quad(\mathbf b\ne\mathbf0).\qquad A,B,C\text{ are collinear}\iff\overrightarrow{AB}=\lambda\overrightarrow{AC}.\]

RelationshipReliable test for nonzero vectors
Parallel\(\mathbf a=\lambda\mathbf b\) or \(\mathbf a\times\mathbf b=\mathbf0\)
Perpendicular\(\mathbf a\cdot\mathbf b=0\)

Use this self-audit to check that each relationship can be recognized, tested and computed. The empty squares are checklist markers, not answer blanks.

RelationshipI can…
Point and line□ test whether a point lies on a line. □ find the foot and shortest distance.
Point and plane□ test whether a point lies on a plane. □ find the foot and shortest distance.
Two lines□ distinguish coincident, parallel, intersecting and skew lines. □ find their acute angle or shortest distance.
Line and plane□ distinguish contained, parallel, intersecting and perpendicular cases. □ find the acute angle and point of intersection.
Two planes□ distinguish coincident, parallel and intersecting planes. □ find their acute angle, distance or line of intersection.
Vector basics□ calculate magnitudes and unit vectors. □ use components and vector algebra laws.
Ratios□ use collinearity and internal-division formulae. □ interpret the ratio orientation correctly.
Scalar product□ test perpendicularity and find an angle. □ distinguish signed projection from projection length.
Vector product□ test parallelism and determine orientation. □ find parallelogram and triangle areas.
Equations□ form line equations from one or two points. □ form plane equations from directions or a normal.
Problem solving□ draw a labelled sketch. □ use a graphing calculator where numerical solving is appropriate.
  1. State nonzero-vector conditions before dividing by a magnitude.
  2. Keep absolute values in distance and acute-angle formulae.
  3. Use one consistent parameter per line and check all components.
  4. Mark only genuine intersections; skew lines do not intersect.
  5. Verify the final point or direction in the original equations.

Need help? Join our JC Math tuition classes.

Learn more