ConceptGeometry & Algebra
← All conceptsVectors
8 ways this goes wrong. Each one is a named misconception the questions are built to catch.
- Cross term dropped in |a+b|Forgets the 2(a.b) term when finding the magnitude of a vector sum.→
- Parallel set components equal not proportionalSets components equal instead of proportional for a parallel-vector condition.→
- Parallel vs perpendicular conditionUses the dot-product (perpendicular) condition when parallel/collinear is required, or vice versa.→
- Polygon vector relation misusedMisuses a hexagon's diagonal/side relations or picks the wrong base-vector combination.→
- Scalar vs projection vectorReports the scalar projection when the projection vector is required (or drops the orthogonal cross term).→
- Vector subtraction order reversedComputes A-B instead of B-A (or adds instead of subtracts) for vector AB.→
- Wrong dot product set to zeroSets the wrong dot product to zero when applying a perpendicularity condition with |a|=k|b|.→
- Wrong included angle usedUses cos of the wrong angle (e.g. 60 vs 120) in the law-of-cosines magnitude.→
