@Rianthe I’ve been asked this question a lot. Besides what’s been stated above (granted, I haven’t read all of the posts), here are some applications:
- You basically need to be familiar with working in other bases (particularly 2 and 16) to study CS, as a low and a high voltage encodes 2 values (hence, binary).
- Linear programming (sometimes introduced in Alg2 or Pre-Calc) is a huge question in computer science, and lots of algorithms have been developed for solving LPs (simplex algorithm, ellipsoid method). Finding the best solution to integer LPs is NP-hard.
- Building/bridge/road design calls for plenty of algebra, trig, calculus, and physics.
- Using vectors and vector-valued functions when designing video game animations.
- Oftentimes when writing a program, instead of repeating or hard-coding stuff, using recursion saves you a lot of time.
5a. Sometimes solving the recursion leads to an easy solution.
- Notes on a keyboard follow a logarithmic scale. For example, A above middle C is tuned to 440 Hz, while the notes one octave higher and lower carry frequencies of 880 Hz and 220 Hz. A lot of professional musicians I know know this.
- Modular arithmetic and the concept of an inverse modulo m is used in RSA encryption. Note that factoring large numbers is still hard.
…and many others.