求值sin68°cos23°-cos68°sin23°=

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求值sin68°cos23°-cos68°sin23°=

sin68°cos23°-cos68°sin23°
=sin(68°-23°)
=sin45°
=√2/2

sin(a-b)=sinacosb-cosasinb
sin68°cos23°-cos68°sin23°=sin(68°-23°)=sin45°=根号2/2

sin68°cos23°-cos68°sin23°
=sin(68°-23°)
=sin45°
=根号2/2

sin68°cos23°-cos68°sin23°=sin(68°-23°)=sin45°=√2/2

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