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sin(p/8)×cos(p/8)=0,5×2sin(p/8)×cos(p/8)=0,5sin(p/4)=0,5(2√2)=√2/4.
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sin(p/8)×cos(p/8)=0,5×2sin(p/8)×cos(p/8)=0,5sin(p/4)=0,5(2√2)=√2/4.