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waterineyesBest ResponseYou've already chosen the best response.8
Let us start from the start..
 one year ago

Mimi_x3Best ResponseYou've already chosen the best response.1
\[cos^{2}2x cos^{2}6x = sin4xsin8x\]?
 one year ago

Mimi_x3Best ResponseYou've already chosen the best response.1
have you tried cos^{2}2x = (1+cos4x)/2?
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
\[\cos^2 A  \cos^2 B = \sin(A+B)\sin(BA)\] This is a standard formula. So, we need a proof right?
 one year ago

MitulBest ResponseYou've already chosen the best response.0
(1+cos4x)/2(1+cos12x)/2 = (1+cos 4x+cos12x+cos4xcos12x)/2 and then defactorize the last term...and factorize the second and third term
 one year ago

Yahoo!Best ResponseYou've already chosen the best response.0
@apoorvk yup proof needed..
 one year ago

MitulBest ResponseYou've already chosen the best response.0
@apoorvk it is cosAcosBand not their squares for standard formula
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
\[\cos^2(2x)  \cos^2(6x) \implies (\cos(2x)  \cos(6x))(\cos(2x) + \cos(6x))\] So: Using: \[\cos(C) + \cos(D) = 2\cos(\frac{C+ D}{2})\cos(\frac{CD)}{2})\] \[\cos(C)  \cos(D) = 2\sin(\frac{C+ D}{2})\sin(\frac{DC}{2})\] \[(2\sin(4x) \sin(2x))(2\cos(4x)\cos(2x)) \implies (2\sin(2x)\cos(2x)) \cdot (2\sin(4x) \cos(4x))\] \[\implies \sin(4x) \cdot \sin(8x)\]
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
Using: \[2\sin(x)\cos(x) \implies \sin(2x)\]
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
I think above you by mistake written (BA) @apoorvk
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
You are doing wrong I guess..
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
Rewrite for cos(A)  cos(B) = ??
 one year ago

Yahoo!Best ResponseYou've already chosen the best response.0
@apoorvk u told me it is sin(a+b).sin(ba) but u have written differ
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
yeah I have memory problems . Amnesia *sigh* *sniff*
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
\[\cos(A)  \cos(B) = 2\sin(\frac{A+B}{2}) \cdot \sin(\frac{BA}{2})\]
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
And not sin(aB) in the last..
 one year ago

Yahoo!Best ResponseYou've already chosen the best response.0
@apoorvk if i use ur method we wont get that lol
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
NOOOOOOOO!!!!!!!!!!!!!!!!!! What have i been doing? /_\
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
Okay please tweak it and use it as needed, we know the procedure atleast. Or should I repost?
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
See: \[\cos^2(2x)  \cos^2(6x) = \sin(A+B)\sin(AB) \implies \sin(2x  6x)\sin(2x + 6x)\] Don't you think we get negative ??? @apoorvk
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
yeah i got it ate already  unfortunately i can't view my raw LateX codes (some stupid bug :\), so I'll have to edit it manually. NOOOOOO!!!!!!!!!
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
Sir what you think is correct, if you want a confirmation. .
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
There must be condition for doing this formula : I am discussing with you @apoorvk
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
The above said formula will work if B > A..
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
\[\cos^2A−\cos^2B\] \[=(\cos A+\cos B)(\cos A−\cos B)\] \[=[2\cos(\frac{A+B}2)\cos(\frac{A−B}2)][2\sin(\frac{A+B}2)\sin(\frac{BA}2)]\] \[=[2\sin(\frac{A+B}2)\cos(\frac{A+B}2)][2\sin(\frac{BA}2\cos(\frac{BA}2)]\] \[=\Large\boxed{\sin(A+B)\sin(BA)}\] Happy nitpickers? ____
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
Do you think It will work ??
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
Water in eyes, Fish in Water \(\large \rightarrow\) so Fish in eyes. _
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
I am asking you @apoorvk
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
If fish is eyes then why are looking upwards?? Is fish in your eyes??
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
I paarsonaaally bilib it's Phaathar bill waark! , (dish phormula)
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
What is this?? @apoorvk
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
U know aandarishtand? oowhaat u know no inglis?? BAH HUMBUG!
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
Inglish pipul go, liebe children behind _
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
'Addition', man, addition > " sin (A '+' B)  Y U LOVE SUBTRACTION??
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
U inglish phail, I inglish oowhale. ____
 one year ago

waterineyesBest ResponseYou've already chosen the best response.8
You failed in english? ok I got this.. Better luck next time.. @apoorvk
 one year ago

apoorvkBest ResponseYou've already chosen the best response.1
Hu shaid I phail in inglish?? U no si mai bandarfool inglish haan??? o.O I gets the 105 out of 100 __ u get how many?
 one year ago
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