计算:cos30°+sin45°+tan60°=
问题描述:
计算:cos30°+sin45°+tan60°=
(1+sin45°+sin30°)(1-cos45°+cos60°)的值是
答
cos30°+sin45°+tan60°
=√3/2+√2/2+√3
=3√3/2+√2/2
(1+sin45°+sin30°)(1-cos45°+cos60°)
=(1+√2/2+1/2)(1-√2/2+1/2)
=(3/2+√2/2)(3/2-√2/2)
=9/4-2/4
=7/4