cos73`sin223`-sin253`sin47`
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cos73`sin223`-sin253`sin47`
![cos73`sin223`-sin253`sin47`](/uploads/image/z/19269388-28-8.jpg?t=cos73%60sin223%60-sin253%60sin47%60)
cos73°sin(-43°)-sin(-73°)cos43°
=sin73°cos43°-cos73°sin43°
=sin(73°-43°)
=sin30°
=1/2
=sin73°cos43°-cos73°sin43°
=sin(73°-43°)
=sin30°
=1/2