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by mathieuh 1363 days ago
I'm 27, educated in the UK, all I remember about trigonometry is SOHCAHTOA.
7 comments

USA here, same acro. I still start off solving by writing it off and drawing slashes through O/H A/H O/A for reference.

Came to use trig functions quite frequently while playing video games, and that was a big surprise to me. Not to assume you've played it, but I've recently discovered that Stormworks is a programmer's game - you can write microcontroller code in LUA for your vehicle designs. And, wow, does it ever use my trig knowledge everywhere.

Realized the transponder beeps can be triangulated, tick being 1/60th of a sec and that's a distance estimate resolution of up to 5-10 km. And that's when cos and sin came back to be useful because you can do intersection of circles and figure out where to do a sea rescue more precisely. So video games, trig. Who would've thought?

The Dutch version was SOSCASTOA, with a picture of a ship called the Castoa sending out an SOS because it was sinking. That picture really helped.

And I even remember what it means:

SOS: sine = opposing side divided by diagonal (schuine) side

CAS: cosine = adjacent divided by diagonal

TOA: tan = opposing divided by adjacent.

I don't think I've ever used it for anything practical, but I can still reproduce it after all this time (I'm 47 now).

> I don't think I've ever used it for anything practical.

Just the other day I wanted to compute viewing angle and did it by hand even though there are plenty of calculators like this out there:

http://www.hometheaterengineering.com/viewingdistancecalcula...

I’d say I use it for something practical/random like that a few times a year?

Another example was placing some ceiling speakers whose tweeters had a 15° angle so that they were pointed directly at a seating position below. How far did I need to place them in front of the seating position from directly overhead.

I would guess any sort of construction you’re using it fairly often.

The one that I still use is the 3-4-5 rule to ensure a right angle. Still use that one to chalk off sporting fields of play.
I use that one all the time, but that's Pythagoras, not sin and cos.
Yeah, I know it's not the same type of math, but it's one of the few things that I still use today. To be honest, I can't think of one time in my professional career that I have needed to calculate the area under a curve to solve a life problem. Geometry has been the most used branch of math past basic arithmetic, oh, and algebra. It amazes me the number of people that don't realize how many times in a day they have solved for X.
It was by no means uncommon when I was taught in the US but I somehow missed it, instead just internalizing the various relationships directly, and was briefly confused when classmates started talking about SOHCAHTOA working together in college math courses.

What I remember from trig is to draw a unit circle. Most of the rest falls out of that.

I’m handy outside of work and use sohcahtoa often enough to remember it. Triangles are everywhere and sometimes you need to compute angles and lengths of sides.

Statistics is also useful and applicable to everyday life, but I didn’t learn that till college as best I can recall.

I don’t regret having spent time learning calc, or physics or chemistry or biology for that matter. If you asked me to come up with a curriculum I’d have a really hard time prioritizing. Maybe the one thing I’d like to see kids learn better is how to be self-directed learners. I’m still fairly surprised at the number of colleagues I have who seem unable to problem solve and figure something the fuck out. Even knowing when and how to ask for help.

I'm a 50+ year old American, of british decent... I never managed to remember the 'american' mnemomic, but my dad taught me one the used to use in England around WWII: Percy has a bald head, poor boy

Perpendicular/hypotanuse = Sin

Base / Hypotanuse: CoSin

Perpendicular / Base: Tan

edit: try to fix the HN god awful formatting

Ha I also remember the mnemonic but I don’t have a clue how to use it.
it's to remember the ratios for trigonometric functions on a right triangle:

Sine: Opposite over Hypotenuse

Cosine: Adjacent over Hypotenuse

Tangent: Opposite over Adjacent

Otto had a heap of apples.