有关两角和与差的正弦余公式的题
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有关两角和与差的正弦余公式的题
sin(x+y)cos(z-y)-cos(y+x)sin(y-z)
sin(x-y)sin(y-z)-cos(x-y)cos(z-y)
sin(x+y)cos(z-y)-cos(y+x)sin(y-z)
sin(x-y)sin(y-z)-cos(x-y)cos(z-y)
![有关两角和与差的正弦余公式的题](/uploads/image/z/13435706-2-6.jpg?t=%E6%9C%89%E5%85%B3%E4%B8%A4%E8%A7%92%E5%92%8C%E4%B8%8E%E5%B7%AE%E7%9A%84%E6%AD%A3%E5%BC%A6%E4%BD%99%E5%85%AC%E5%BC%8F%E7%9A%84%E9%A2%98)
sin(x+y)cos(z-y)-cos(y+x)sin(y-z)
=sin(x+y)cos(y-z)-cos(x+y)sin(y-z)
=sin[(x+y)-(y-z)]
=sin(x+z)
sin(x-y)sin(y-z)-cos(x-y)cos(z-y)
=sin(x-y)sin(y-z)-cos(x-y)cos(y-z)
=-[cos(x-y)cos(y-z)-sin(x-y)sin(y-z)]
=-cos[(x-y)+(y-z)]
=-cos(x-z)
=sin(x+y)cos(y-z)-cos(x+y)sin(y-z)
=sin[(x+y)-(y-z)]
=sin(x+z)
sin(x-y)sin(y-z)-cos(x-y)cos(z-y)
=sin(x-y)sin(y-z)-cos(x-y)cos(y-z)
=-[cos(x-y)cos(y-z)-sin(x-y)sin(y-z)]
=-cos[(x-y)+(y-z)]
=-cos(x-z)