求值：sin15°cos5°−sin20°cos15°cos5°−cos20°

求值：cos20°sin20° cos65°-sin80°sin15°/cos5°-co.. 化简：cos20°cos35°1−sin20° 求cos15°-tan15°/cos15°+sin15° 1/cos20°-根号3/sin20° 求值：[2sin50°+sin80°（1+√3tan10°）]/√2cos5° 求值(sin9°cos15°-sin24°)/(sin9°sin15°+cos24°) 求值:(sin9°+sin6°cos15°)/(cos9°-sin6°sin15°) 求值：（sin20°-sin40°）/cos20°-cos40°） (sin10°+sin20°)/(cos10°+cos20°)化简求值 (cos15°-cos75°)(sin75°+sin15°)＝? tan15°+cos15°/sin15°的值 求详解