Trig Identity Proof (1 Viewer)

凍鴛鴦

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Hi,

How do you proof that

LHS = RHS given

LHS = Sqrt(3)*Cos[3t]-Sin[3t]
RHS = 2Cos[3t + pi/6]

??

Thanks!
 

Jago

el oh el donkaments
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auxiliary angle method i presume.

aka let root3 Cos3t - Sin3t = Rcos(x + @)
 

haboozin

Do you uhh.. Yahoo?
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凍鴛鴦 said:
Hi,

How do you proof that

LHS = RHS given

LHS = Sqrt(3)*Cos[3t]-Sin[3t]
RHS = 2Cos[3t + pi/6]

??

Thanks!
expand RHS

2(cos3tcos(pi/6) -sin3tsinpi/6)

2Sqrt(3)/2cos3t - 2/2sin3t

sqrt(3)cos3t - sin3t = LHS
 

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