Task/25095688
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Докажите тождество
cos(2π - α)*( tg(3π/2 -α) )²*tg(π+α)*( ctg(π/2+α) )² +cos(5π/2 +α) =0 .
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* * * cos(5π/2 +α) =cos( (2π +(π/2 +α) ) =cos(π/2 +α) = - sinα * * *
cos(2π - α)*( tg(3π/2 -α) )²*tg(π+α)*( ctg(π/2+α) )² +cos(5π/2 +α) =
cosα*(ctgα)² *tgα*(-tgα)² - sinα =cosα*tgα*(ctgα *tgα)² - sinα =
cosα*(sinα/cosα)*1² -sinα =sinα -sinα =0 .
0 =0
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применены формулы приведения