Calculus I Equation Sheet


Basic Derivative Rules

Rule Function Form Derivative Form
Constant \(c\) \(0\)
Power \(x^n\) \(n x^{n-1}\)
Constant Multiple \(c \cdot f(x)\) \(c \cdot f'(x)\)
Sum \(f(x) + g(x)\) \(f'(x) + g'(x)\)
Difference \(f(x) - g(x)\) \(f'(x) - g'(x)\)
Product \(f(x)g(x)\) \(f'(x)g(x) + f(x)g'(x)\)
Quotient \(\dfrac{f(x)}{g(x)}\) \(\dfrac{f'(x)g(x) - f(x)g'(x)}{g(x)^2}\)
Chain \(f(g(x))\) \(f'(g(x)) \cdot g'(x)\)
Inverse \(f^{-1}(x)\) \(\dfrac{1}{f'(f^{-1}(x))}\)

Trigonometric Derivatives

Function Derivative
\(\sin x\) \(\cos x\)
\(\cos x\) \(-\sin x\)
\(\tan x\) \(\sec^2 x\)
\(\sec x\) \(\sec x \tan x\)
\(\csc x\) \(-\csc x \cot x\)
\(\cot x\) \(-\csc^2 x\)

Exponential & Logarithmic Derivatives

Function Derivative
\(a^x\) \(a^x \ln(a)\)
\(e^x\) \(e^x\)
\(a^{g(x)}\) \(g'(x)\, a^{g(x)} \ln(a)\)
\(e^{g(x)}\) \(g'(x)\, e^{g(x)}\)
\(\log_a(x)\) \(\dfrac{1}{x \ln(a)}\)
\(\ln(x)\) \(\dfrac{1}{x}\)
\(\log_a(g(x))\) \(\dfrac{g'(x)}{g(x)\ln(a)}\)
\(\ln(g(x))\) \(\dfrac{g'(x)}{g(x)}\)

Average Rate of Change

\[ AV_[a,b] = \frac{f(b) - f(a)}{b-a} \]

Limit Definition of a Derivative

\[ f'(a) = \lim_{h \to 0} \frac{f(a+h) - f(a)}{h} \]


General Functions & Forms

  • Linear Forms:
    General: \(f(x) = ax+b\),
    Point-slope: \(y-y_1 = m(x-x_1)\),
    Slope-intercept: \(y=mx+b\)

  • Quadratic Forms:
    General: \(ax^2+bx+c\),
    Vertex: \(a(x-h)^2+k\),
    Roots: \(\dfrac{-b \pm \sqrt{b^2-4ac}}{2a}\)

  • Polynomial (nth-order):
    \(f(x) = a_nx^n + \dots + a_1x + a_0\)

  • Transformations:
    \(g(x) = a f(x-b) + c\)

  • Sinusoid:
    \(f(x) = a \sin(kx+b)+c,\ \ T=\dfrac{2\pi}{k}\)


Applications

  • Slope of tangent line: \(m = f'(a)\)
  • Tangent line equation: \(y = f'(a)(x-a)+f(a)\)
  • Linear approximation: \(L(x)=f(a)+f'(a)(x-a)\)
  • Related rates: \(\dfrac{dy}{dt} = \dfrac{dy}{dx}\cdot\dfrac{dx}{dt}\)
  • Concavity: \(f''>0 \Rightarrow\) concave up, \(f''<0 \Rightarrow\) concave down
  • Extrema: solve \(f'(x)=0\), check sign of \(f'\) or use \(f''\)