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[tex]4sin36^{o} * cos6^{o} + 4sin^{2}24^{o} -4[/tex]
4sin(90-54)*cos6 + 4sin^2(24) - 4=4cos54*cos6 + 4sin^2(24) - 4 =
=4*(1/2)*(cos48 + cos60) + 4sin^2(24) - 4 = 2cos48 +1 + 4sin^2(24) - 4 =
= 2cos^2(24) -2sin^2(24) + 1 + 4sin^2(24) - 4 = 2cos^2(24) +2sin^2(24) - 3 =
= 2 (cos^2(24) + sin^2(24)) - 3 = 2 - 3 = 1
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4sin(90-54)*cos6 + 4sin^2(24) - 4=4cos54*cos6 + 4sin^2(24) - 4 =
=4*(1/2)*(cos48 + cos60) + 4sin^2(24) - 4 = 2cos48 +1 + 4sin^2(24) - 4 =
= 2cos^2(24) -2sin^2(24) + 1 + 4sin^2(24) - 4 = 2cos^2(24) +2sin^2(24) - 3 =
= 2 (cos^2(24) + sin^2(24)) - 3 = 2 - 3 = 1