Exam Strategy
Readiness Check
You are ready when you can:
- Simplify $b^m b^n$, $(b^m)^n$, $b^{-n}$, and $b^{1/k}$ without a calculator.
- Rewrite $f(x)=a\cdot b^{x+k}$ and $f(x)=a\cdot b^{cx}$ into equivalent $ab^x$ forms.
- Explain one graphical consequence of each property.
On the AP Exam
- MCQ: pick the equivalent expression; identify which transformation matches a rewrite.
- FRQ: show equivalence steps; justify base change; connect to context (preview 2.5).
- Skills: 1.B equivalent forms; 3.A describe features after rewriting.
Tactics
1. Factor to a common base first ($4^x=(2^2)^x=2^{2x}$). 2. For $b^{x+k}$, pull out $b^k$ as a vertical multiplier. 3. For $b^{cx}$, rewrite base as $b^c$ before comparing growth. 4. Negative exponents: move to denominator immediately. 5. Roots: $b^{1/k}=\sqrt[k]{b}$; combine with power property.
Common Traps
- Illegal exponent addition with mismatched bases.
- Confusing shift $b^{x+k}$ with power $(b^x)^k$.
- Forgetting that $b^{cx}=(b^c)^x$ requires $b>0$ for standard reals.
Quick Checklist
- [ ] Common base identified
- [ ] Correct rule applied (product / power / negative / root)
- [ ] Equivalent $ab^x$ form if asked
- [ ] Graph transformation named if asked