Exam Strategy
Readiness Check
You are ready when you can:
- Find `<a,b>` from two points and compute magnitude.
- Add vectors and scalar multiply by components.
- Compute dot product and test perpendicularity.
- Write unit vector and ai + bj form.
Course vs AP Exam
Course scope only (Unit 4 additional topic; not on the AP Exam). These skills still matter for Unit 4 coursework and readiness for 4.9.
Tactics (course assessments)
1. Label tail and head before components. 2. Magnitude: `sqrt(a^2+b^2)`. 3. Sum: add like components; graph tip-to-tail. 4. Dot: `a1*a2 + b1*b2`. 5. Perpendicular nonzero vectors: dot product 0.
Common Traps
- `P2 - P1` vs `P1 - P2` reversed.
- Forgetting to divide by magnitude for unit vector.
- Using dot product formula with wrong angle reference.
- Scalar multiply affects both components.
Quick Checklist
- [ ] Components from correct tail-to-head
- [ ] Magnitude computed correctly
- [ ] Operations on components, not just lengths
- [ ] Dot product interpreted correctly
- [ ] Unit vector direction preserved