Exam Strategy
Readiness Check
You are ready when you can (1) write $a$ and $b$ from $f(x)=ab^x$, (2) classify growth/decay, (3) state domain and end behavior, (4) describe monotonicity and concavity, and (5) deny global extrema/inflection on $\mathbb{R}$.
Prep Sequence
1. Ten classify growth/decay drills. 2. Five limit-statement items. 3. Five ratio-table verifications. 4. Three "extrema on $\mathbb{R}$?" questions. 5. Two shifted-form reads ($a b^{x-h}$).
On the Exam
- Start with $f(0)=a$.
- Compare $b$ to 1 for growth vs decay.
- For limits: track whether outputs blow up or approach 0.
- If asked about max/min on all reals: "none" unless a closed interval is specified.
- Proportional outputs over equal $\Delta x$ => exponential.
Common Traps
- Calling decay "negative slope linear."
- Missing that $0<b<1$ still means exponential decay, not "not exponential."
- Forgetting $\lim_{x\to-\infty} b^x$ when $b>1$ is 0.
- Claiming an inflection point.
Quick Checklist
- [ ] $a\neq 0$, $b>0$, $b\neq 1$
- [ ] Growth/decay correct
- [ ] Domain all reals stated
- [ ] Limits/end behavior stated
- [ ] No unjustified extrema/inflection on $\mathbb{R}$