Remember trig functions fast

[wise tundra]

hey guys I need to memorize all these by tomorrow(except the sin^2 and cos^2 anyone have any tricks/mnemonics/videos or anything??!

[steel hedge]

I'm not sure I know how to do memorize it fast, but I'd encourage you to learn how people derived these @wise tundra .

They're not too complicated

Basically, most (if not all iirc) identities were derived from the sin(A+B) formula

so learn how to derive those, and just memorize sin(A+B).

[spare gale]

u could easily understand it if u know how to prove them and then u can remember them

that is my tip

[mortal peak]

I know, it's maybe not a good advice, but try to derive the formulas. LOL, I didn't read the other answers. Still it's better to know how they're working, and how we get them instead of just looking for them in your memory void. Better if you'll draw some mindmap. Math isn't about the rules, but the system, like puzzle

[plush sequoia]

id personally just try to derive them myself so that i get a sense of why these formulae work

[dusty void]

For me i just use euler's formula to find trig formulas quickly with the exponential, its quick and you dont need to memorize anything at all which is cool
For a mnemonic way what we say in France is:

Cos is mean so he segregates everyone and turns + into - and vice versa:
so cos a+b = cos a cos b - sin a sin b
Sin is the opposite, he's nice:
so sin a+b = sin a cos b + sin b cos a

For the double angle identities you just do cos 2A = cos A+A and do the sum formula
(and just remember that cos^2 a + sin^2 a = 1 always)

for tan you can write as sin/cos and find the rest
and the half angle formulas are literally the double angle formulas but shifted around

so thats all :)

Good luck memorizing 💪

[steel hedge]

OP, what @bove described was how to derive them hopefully this helps!

[dusty void]

(i also gave mnemonics 😅 )

[steel hedge]

I noticed

[wise tundra]

thanksss so much

[steel hedge]

If you are done, type .solved. You are always more than welcome to ask more questions here

[robust valve]

Based on the formulas you wrote, this is my advice.
Understand, then Memorize the Sum and Difference Formulas
Then, use them to write the Double-Angle and Half-Angle Formulas.
Do you know how to write the Double-Angle and Half-Angle Formulas based on only the Sum/Difference Formulas?

[wise tundra]

yepp, I’ve got it mostly down

I’ll just do some practice later to make sure I remember correctly

[robust valve]

Okay, cool. I wish you well.

[wise tundra]

thanksss

[wise tundra]

alright, appreciate it

u guys explain these stuff better than my teacher😅

.solved