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apple_pi
 3 years ago
Simplify
sin^2(54)+cos^2(72)
apple_pi
 3 years ago
Simplify sin^2(54)+cos^2(72)

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apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0Please don't just go sin 54 = blah and cos(72) = blah, so blah + blah = blahblah

tukajo
 3 years ago
Best ResponseYou've already chosen the best response.0is 54 the actual number or is that in 54 degrees?

zzr0ck3r
 3 years ago
Best ResponseYou've already chosen the best response.0So you just want to know how to computte this by hand?

apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0why did you go into radians?

apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0so what is x equal to?

tukajo
 3 years ago
Best ResponseYou've already chosen the best response.0I fluttered that up ignore me.

tukajo
 3 years ago
Best ResponseYou've already chosen the best response.0Hopefully zrocker can help you X_X

Callisto
 3 years ago
Best ResponseYou've already chosen the best response.3\[sin^2(54)+cos^2(72)\]\[=(cos(9054))^2+cos^2(72)\]\[=cos^2(36)+cos^2(72)\] That looks nicer

apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0Oh, wait... let me try now

apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0cos^2(36) + (2cos^2(36)1)^2

apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0now... do we evaluate cos(36) or simplify more?

apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0ok. is this straightforward or something we fancily work out?

Callisto
 3 years ago
Best ResponseYou've already chosen the best response.3let x = 36 5x = 180 3x = 180  2x sin 3x = sin2x 3 sinx  4sin^3 x = 2sinx cox Since sinx =/= 0 3 4 sin^2 x = 2cosx 3 4 ( 1cos^2 x) = 2 cos x 4 cos^2 x  2cosx 1 =0 Now, solve for cosx.

Callisto
 3 years ago
Best ResponseYou've already chosen the best response.3@apple_pi Come back :'(

zzr0ck3r
 3 years ago
Best ResponseYou've already chosen the best response.0So in what class do we learn to play with this trick?

Callisto
 3 years ago
Best ResponseYou've already chosen the best response.3I'm sorry, I don't know. I'm not from the US. But for me, I learnt it two years before university.

apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0Sorry... I had to go for a while

apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0Yeah that solved it! Thanks @Callisto

Callisto
 3 years ago
Best ResponseYou've already chosen the best response.3You're welcome. FYI, this post is worth looking! http://openstudy.com/study#/updates/4fe6e718e4b02c91101b52cd

apple_pi
 3 years ago
Best ResponseYou've already chosen the best response.0Got another one: http://openstudy.com/study#/updates/50827553e4b0dab2a5ebddaa
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