引用：原式=√[(sin5°)^2+2sin5°cos5°+(cos5°)^2]+√[(sin5°)^2- 2sin5°cos5°+(cos5°)^2]=√(sin5°+cos5°)^2+√(sin5°-cos5°)^2=sin5°+cos5°+cos5°-sin5°=2cos5°.因cos5°>sin5°,|sin5°-cos5°|=...