6cos30°×tan 30°-2sin²45 °
问题描述：
6cos30°×tan 30°-2sin²45 °
答
6cos30°×tan 30°-2sin²45 °
=6×√3/2×√3/3-2×（√2/2）²
=3-1
=2
答
=6 sin30° - 2 sin²45 °
=6×1/2-2×（√2/2）²
=3-2×1/2
=2