Exam Strategy
Readiness Check
- Compute $\dfrac{f(b)-f(a)}{b-a}$ from a formula, table, or graph.
- State units and interpret the sign in context.
- Compare average rates on two intervals.
- Estimate rates from a graph using readable points.
Before the Exam
1. Drill AROC from formulas with messy numbers (fractions, negatives). 2. Drill table problems: only use the two endpoints given for the interval. 3. Practice one "units + meaning" sentence after every applied rate. 4. Compare rates: which interval has larger magnitude? which is more positive?
During Multiple Choice
- Identify $a$ and $b$ first; wrong endpoints are a common trap.
- Check order: numerator is change in output; denominator is change in input.
- Eliminate choices with wrong units or impossible signs.
- For "closest estimate," pick graph points you can actually read.
During Free Response
1. Write the AROC expression with substituted values. 2. Simplify and include units when the stem is applied. 3. Interpret: "On average, ... increased/decreased by ... per ..." 4. If comparing intervals, compute both rates, then conclude with inequality language.
Common Traps
- Using $f(a)-f(b)$ instead of $f(b)-f(a)$.
- Dividing by $a-b$ instead of $b-a$.
- Reporting $\Delta y$ or $\Delta x$ alone as the rate.
- Mixing consecutive table gaps when the interval is not consecutive.
60-Second Checklist
- Correct endpoints?
- Correct orientation of fraction?
- Units stated?
- Sign matches increase/decrease?
- Comparison uses both computed rates?