TR3.5

Deravitaves

Houjun Liu 2021-09-27 Mon 12:00

1 Derivatives

=> Instantaneous rate of change at a particular point

  • Average rate of change = \(\frac{\Delta Y}{\Delta X}\)

rateofchange.png

Figure 1: rateofchange.png

  • Instantaneous rate of change = \(\lim_{\Delta x \to 0} \frac{\Delta Y}{\Delta X}\)

Derivative of \(f(x)\) => \(\frac{dy}{dx}\)

derivativesWB.png

Figure 2: derivativesWB.png

1.1 Useful Table of Derivatives

f(x) f'(x)
\(x^2\) \(2x\)
\(x^3\) \(3x^2\)
\(x^n\) \(nx^{n-1}\)
\(\frac{1}{x}\) \(\frac{-1}{x^2}\)
\(\sqrt{x}\) \(\frac{1}{2 \sqrt{x}}\)
\(\sin(x)\) \(\cos (x)\)
\(\cos(x)\) \(-\sin (x)\)
\(\tan(x)\) \(1 + \tan^2 (x) = sec^2(x)\)
\(\cot(x)\) \(-\csc^2 (x)\)
\(\sec(x)\) \(\tan(x) \sec(x)\)
\(\csc(x)\) \(-\cot(x) \csc(x)\)
\(e^x\) \(e^x\)
\(ln(x)\) \(\frac{1}{x}\)
\(a^x\) \(a^x ln(a)\)
\(log_a(x)\) \(\frac{1}{x ln(a)}\)
\(f^-1(x)\) \(\frac{1}{f'(f^-1(x))}\)
\(sin^-1(ax)\) \(\frac{a}{\sqrt{1-(ax)^2}}\)
\(cos^-1(ax)\) \(\frac{-1}{\sqrt{1-(ax)^2}}\)
\(tan^-1(ax)\) \(\frac{1}{1+(ax)^2}\)