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If sinA=1/2, show that 3cosA-4cos3A=0

since sinA=1/2;therefore  hypotenuse = 2 and opposite side of <A=1...;therfore 3cosA=3 x root3/2;which is equal to 4cos3A...therfore 3cosA-4cos3A=0

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cosA root under 1-sin2A=0.4

now from LHS=3*0.4-4*(0.04)3

  =1.2-0.256

  =0.somthing that mean 0 ans

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