Exam Strategy
Readiness Check
You are ready when you can:
- State right/left from x(t) and up/down from y(t) on an interval.
- Explain that direction can change with t.
- Compare two parametrizations of the same curve.
- Compute average ROC and secant slope with justification.
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 4.4.
Tactics (course assessments)
1. Write t1, t2 and evaluate x, y at both ends. 2. Sign of Delta x --> right/left; sign of Delta y --> up/down. 3. Average ROC: (component change) / (t2 - t1). 4. Secant slope = (avg ROC y) / (avg ROC x) when avg ROC x != 0. 5. Support answers with table values or short rationale (3.C).
Common Traps
- Swapping x and y direction rules.
- Using Delta x / Delta t as secant slope in the xy-plane.
- Dividing when average ROC of x is zero.
- Ignoring that direction depends on the t-interval chosen.
Quick Checklist
- [ ] Direction from x and y analyzed separately
- [ ] Interval endpoints evaluated
- [ ] Average ROC computed correctly
- [ ] Secant slope only when avg ROC x != 0
- [ ] Conclusion supported with data