Cosπ cosπ cosπ cos23π = 1
12 24 48 48 16
По действиям:
1) cos π cos23π =1 * cos( π +23π) + cos(π - 23π) =
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=1 * (cosπ + cos(-22π)) = 1 * cos11π
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2) cos π *1 * cos 11π = 1 * 1 * (cos( π + 11π) + cos( π -11π)) =
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=1 * (cos π + cos(-10π))= 1 * cos5π
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3) cos π * 1 * cos5π = 1 * 1 * (cos( π+5π)+cos( π - 5π)) =
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= 1 * (cos π +cos(-4π)) = 1 * cos π = 1 * 1 = 1
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