cos80°cos35°+cos10°cos55° 化简求值
cos80°cos35°+cos10°cos55° 化简求值
cos80°cos35°+cos10°cos55° 化简求值
cos80°cos35°+cos10°cos55° 化简求值
cos80°cos35°+cos10°cos55°
=cos80°cos35°+sin80°sin35°
=cos(80°-35°)
=cos45°
=√2/2
cos80°cos35°+cos10°cos55°
=sin10°cos35°+cos10°sin35°
=sin(10°+35°)
=sin45°
=√2/2。(tan55°-tan10°)÷(1+tan55°×tan10°)化简sin15°-cos15°