AP Calculus AB / BC — All Units
L'Hôpital's Rule: If \(\frac{f(x)}{g(x)} \to \frac{0}{0}\) or \(\frac{\infty}{\infty}\), then:
Continuity at \(x=a\): (1) \(f(a)\) exists, (2) \(\lim_{x\to a}f(x)\) exists, (3) \(\lim_{x\to a}f(x)=f(a)\).
Limit definition:
Chain Rule: \(\dfrac{d}{dx}[f(g(x))] = f'(g(x))\cdot g'(x)\)
Implicit Differentiation: Differentiate both sides w.r.t. \(x\); treat \(y\) as a function of \(x\), so \(\dfrac{d}{dx}[y^n]=ny^{n-1}\dfrac{dy}{dx}\).
Mean Value Theorem: If \(f\) is continuous on \([a,b]\) and differentiable on \((a,b)\), there exists \(c\in(a,b)\) such that:
Related Rates: Differentiate an equation relating quantities with respect to time \(t\). Use the chain rule.
FTC Part 1: \(\dfrac{d}{dx}\!\displaystyle\int_a^x f(t)\,dt = f(x)\)
FTC Part 2: \(\displaystyle\int_a^b f(x)\,dx = F(b)-F(a)\)
Area between curves: \(\displaystyle\int_a^b[f(x)-g(x)]\,dx\) where \(f(x)\ge g(x)\).
Disk Method (about x-axis):
Integration by Parts: \(\displaystyle\int u\,dv = uv - \int v\,du\)
Partial Fractions: Decompose rational functions into simpler fractions before integrating.
Polar area:
p-Series: \(\displaystyle\sum_{n=1}^\infty\frac{1}{n^p}\) converges if \(p>1\), diverges if \(p\le 1\).
Taylor series for \(\sin x\):
Taylor series for \(e^x\):
Separable DE: Separate variables, integrate both sides.
Exponential model: \(\dfrac{dy}{dt}=ky \;\Rightarrow\; y=Ce^{kt}\)
Logistic growth:
As \(t\to\infty\), \(P\to M\) (carrying capacity).