Symbols, subscripts, etc.?

I just keep a bunch of characters in a text file and cut and paste as needed. On my mac, the most common ones are directly accessible via option characters, such as Ωç√∫µºåß∂ƒ©∆œ∑®†¥øπ and more

text file:

Super: ⁰ ¹ ² ³ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹ ⁻ ™ ⁺

Sub: ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉

Money: ∈ ∉ £ ¢ ¥ € $

Greek: Αα Ββ Γγ Δδ Εε Ζζ Ηη Θθ Ιι Κκ Λλ

Μμ Νν Ξξ Οο Ππ Ρρ Σσ Ττ Υυ Φφ Χχ Ψψ ΩωƱ

smaller: ʙ c ᵢ κ ʟ ｏo ʀᵣ s ᵤ vᵥ w x ʏ z

super: ᴬª ᴮᵇ ᴰᵈ ᴱᵉ ᴳᵍ ᴴʰ ᴵⁱ ᴶʲ ᴷᵏ ᴸˡ ᴹᵐ

ᴺⁿ ᴼᵒ ᴾᵖ P ʳᴿ ˢ�� ᵗ ᵁᵘ ᵛ ʷᵂ ˣ ʸ

Math: ∫ ≈ ∼ ± ∓ √ ∛ ∜ ∂ ≠ ∇ ∆ ≤ ≥ ∼ ∞ ∝

✚ × ÷ ≠ ↑↓↑ ½ ⅓ ⅔ ¼ ¾ ⅜ · • × ⧸ / ℓ

https://tools.oratory.com/altcodes.html

I use the LaTeX (a math typesetting program) convention of underscore for subscript and caret for superscript. Most people follow that convention.

Thus, x * x = x^2.

And x_0, x_1, x_2 represents x with subscripts 1, 2, 3.

I similarly use text conventions for other expressions like summation, integration, greek letters, etc. I find most times when people attempt to actually typeset mathematical symbols, it is often garbled and ends up confusing the reader. It tends to irritate me.

So:

delta-T

sin(theta)

150 deg

integral (x = 1,infinity) sin(x) dx

sum(k=1,n) a_n x^n/n!

I do occasionally use a small letter o for a couple of things. It is useful as the symbol for function composition, (f o g), and two of them together make a convincing infinity symbol: [0,oo]