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sin^230°+2sin^260°+tan45°-tan60°+cos^230°=
人气:386 ℃ 时间:2020-05-25 00:41:55
解答
原式=sin²30°+2sin²60°+tan45°-tan60°+cos²30°
=(1/2)²+2×(√3/2)²+1-√3+(√3/2)²
=1/4+2×3/4+1-√3+3/4
=1/4+3/2+1-√3+3/4
=2+3/2-√3
=(7-2√3)/2
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