数学
EMC
$E = mc^2$
Fibonacci
$F_n = F_{n-1} + F_{n-2}$
fn = n => n < 2 ? n : fn(n-1) + fn(n-2)
Golden ratio
$\phi = \frac{1 + \sqrt{5}}{2}$
Euler’s formula
$e^{i\pi} + 1 = 0$
Fourier series
$ f(t) = a_0 + \sum_{n=1}^{\infty} (a_n \cos(nt) + b_n \sin(nt))$
Fast Fourier Transform
$X_k = \sum_{n=0}^{N-1} x_n e^{-i 2 \pi k n / N}$
Metric prefixes
| Name | Symbol | Base 10 | Decimal |
|---|---|---|---|
| quetta | Q | $10^{30}$ | 1000000000000000000000000000000 |
| ronna | R | $10^{27}$ | 1000000000000000000000000000 |
| yotta | Y | $10^{24}$ | 1000000000000000000000000 |
| zetta | Z | $10^{21}$ | 1000000000000000000000 |
| exa | E | $10^{18}$ | 1000000000000000000 |
| peta | P | $10^{15}$ | 1000000000000000 |
| tera | T | $10^{12}$ | 1000000000000 |
| giga | G | $10^9$ | 1000000000 |
| mega | M | $10^6$ | 1000000 |
| kilo | k | $10^3$ | 1000 |
| hecto | h | $10^2$ | 100 |
| deca | da | $10^1$ | 10 |
| $10^0$ | 1 | ||
| deci | d | $10^{−1}$ | 0.1 |
| centi | c | $10^{−2}$ | 0.01 |
| milli | m | $10^{−3}$ | 0.001 |
| micro | $\mu$ | $10^{−6}$ | 0.000001 |
| nano | n | $10^{−9}$ | 0.000000001 |
| pico | p | $10^{−12}$ | 0.000000000001 |
| femto | f | $10^{−15}$ | 0.000000000000001 |
| atto | a | $10^{−18}$ | 0.000000000000000001 |
| zepto | z | $10^{−21}$ | 0.000000000000000000001 |
| yocto | y | $10^{−24}$ | 0.000000000000000000000001 |
| ronto | r | $10^{−27}$ | 0.000000000000000000000000001 |
| quecto | q | $10^{−30}$ | 0.000000000000000000000000000001 |