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Cos t(sec t - cos t)

simplify the expression

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Remember:
sec t=1/cos t
sin²t+cos²t=1 ⇒sin²t=1-cos² t

Therefore:
cos t(sec t- cost)=(cos t* sec t)- cos² t=(cos t * 1/cos t)-cos² t=1-cos²t=sin² t

Answer: cos t(sec t-cos t)=sin² t

User Alexander Gonchiy
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