sin15度-cos15度
=根号2×(根号2)/2×(sin15度-cos15度)
=根号2×[sin15度×(根号2)/2-cos15度×(根号2)/2]
=根号2×[sin15度×cos45度-cos15度×sin45度]
=根号2×sin(15°-45°)
=根号2×sin(-30°)
=根号2×(-1/2)
=-(根号2)/2
希望对您有所帮助
sin15度-cos15度
=根号2×(根号2)/2×(sin15度-cos15度)
=根号2×[sin15度×(根号2)/2-cos15度×(根号2)/2]
=根号2×[sin15度×cos45度-cos15度×sin45度]
=根号2×sin(15°-45°)
=根号2×sin(-30°)
=根号2×(-1/2)
=-(根号2)/2
希望对您有所帮助