第5部 数学公式集
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$cos\theta \;cos\phi=\frac{cos(\theta-\phi)+cos(\theta+\phi)}{2}$ | ||||
$sin\theta \;sin\phi =\frac{cos(\theta-\phi)-cos(\theta+\phi)}{2}$ | ||||
$sin\theta \;cos\phi=\frac{sin(\theta+\phi)+sin(\theta-\phi)}{2}$ | ||||
$cos\theta \;sin\phi=\frac{sin(\theta+\phi)-sin(\theta-\phi)}{2}$ |