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tanjung
Group Title
Help...
Prove that sin36 degrees = sqrt[10  2*sqrt(5)]/4
 one year ago
 one year ago
tanjung Group Title
Help... Prove that sin36 degrees = sqrt[10  2*sqrt(5)]/4
 one year ago
 one year ago

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micahwood50 Group TitleBest ResponseYou've already chosen the best response.0
HINT: 180º/5 = 36º
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
next, what's formula using i do
 one year ago

micahwood50 Group TitleBest ResponseYou've already chosen the best response.0
Seems like it won't help. Try this, using the formula sin (a + b) = cosa sinb + cosb sin a sin36º = 2 sin18º cos18º = 2 cos72º sin72º
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
ok, i know that formula.. but i think we get the new problem... because sin/cos 18 or sin/cos 72 not eassy to get.. it's very difficul, right ?
 one year ago

micahwood50 Group TitleBest ResponseYou've already chosen the best response.0
It seems so. Bump your question to get more helps. Maybe someone can help you with this.
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
ok, thanks...
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
@cwrw238 , @experimentX , @estudier , @Hero , @Zarkon , @sauravshakya , @all... help me please, how to get it
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
any idea guys ?
 one year ago

ajprincess Group TitleBest ResponseYou've already chosen the best response.1
dw:1350231015827:dwdw:1350231152168:dw Use quadratic formula dw:1350231253477:dw dw:1350231349862:dw
 one year ago

experimentX Group TitleBest ResponseYou've already chosen the best response.1
@ajprincess try thisdw:1350231460480:dw
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
ok, i get dw:1350231717622:dw
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
upss. sorry, divided 8
 one year ago

ajprincess Group TitleBest ResponseYou've already chosen the best response.1
dw:1350231971343:dwdw:1350232035700:dw
 one year ago

ajprincess Group TitleBest ResponseYou've already chosen the best response.1
@experimentX I tried bt it is a bit complex. cos sin3x=sin108.
 one year ago

ajprincess Group TitleBest ResponseYou've already chosen the best response.1
Getting it @tanjung?
 one year ago

experimentX Group TitleBest ResponseYou've already chosen the best response.1
this should be simpler ... sin(3x) = sin(2x)
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
not yet, what should i do after that
 one year ago

experimentX Group TitleBest ResponseYou've already chosen the best response.1
since this is just double angle and triple angle ... change everything back to sin ... and remove all roots and try to factorize it.
 one year ago

ajprincess Group TitleBest ResponseYou've already chosen the best response.1
dw:1350232254804:dw
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
so, just take positive sign in sqrt ?
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
i know that + it means there are two number here. what about u for it
 one year ago

mukushla Group TitleBest ResponseYou've already chosen the best response.0
with positive sign u have sin 36>1 thats impossible
 one year ago

ajprincess Group TitleBest ResponseYou've already chosen the best response.1
dw:1350233305717:dw
 one year ago

tanjung Group TitleBest ResponseYou've already chosen the best response.0
oh yea, i understand now... thank u very much for ur help , @ajprincess and @mukushla
 one year ago
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