Why math ?
I have severe tinnitus, Similar to what it would be like when I’m standing on a giant generator machine running at full capacity, sharp and piercing.
it can only be relieved by deep sleep and concentration, especially when I’m engrossed in math and computer programming and I can’t feel the annoying noise in my ears.
Writing Mathematics symbols
Word - insert - formula
basic concepts
We should assess skills and knowledge in the following areas:
khan academy：Equations vs. functions
Function vs Formula - What’s the difference? | WikiDiff
Formula:
generally refers to an equation relating one mathematical expression to another, with the most important ones being mathematical theorems.
通常是指将一个数学表达式与另一个数学表达式相关的方程，其中最重要的是数学定理。指那些表示兩個量之間等或不等的公式。
- 同样是个广义概念. 可以指功能, 一种把自然的事物抽象出来的思想, 或某个数学表达式;
由特定逻辑规则的语言构造而成. 可以是数学公式, 化学式, 逻辑表达式…
如 $y=x^2; x*x$; 氢气+氧气 = 水; Total fruit = number of Apples + number of Oranges; $p->q; q v -q$ 都是 formula, 不一定要有 ‘=’ 号 ;
Equation:
a mathematical formula that expresses the equality of two expressions, by connecting them with the equals sign =. 可以简单的理解为含有未知数的等式，即含有一个以上的未知数并结合等号的数学公式（formula）。
- 和formula 一样也是一个广义概念, 比如 chemical equation. 但一般指数学概念, 用来表示2个expression相等;
Function:
- 在数学里 function 表达的是 ‘在某个动作 f 的作用下, 自变量 x 和 依赖变量 y 的联系(每一个自变量 x 都映射到唯一的 y). 这是一种抽象的思想, 不过也可以说某个数学表达式如 $y=x^2, y-x^2=0$ 是 function.
Functions
hyperbolic-functions
Sequences
Fibonacci sequence Calculator
$F_n = F_(n-1) + F_(n-2)$
Formula
$$F_n=(φ^n−(1−φ)^n)/\sqrt{5}$$
$F_n$ denotes Fibonacci number to be calculated.
φ = 1.618034 Golden ratio
eg.
$F_1=1, F_0=1$
n=10
$F_n = 89$