sin^230°+2sin^260°+tan45°-tan60°+cos^230°=

来源:学生作业帮助网 编辑:六六作业网 时间:2024/07/10 10:07:31
sin^230°+2sin^260°+tan45°-tan60°+cos^230°=sin^230°+2sin^260°+tan45°-tan60°+cos^230°=sin^230°+2sin^26

sin^230°+2sin^260°+tan45°-tan60°+cos^230°=
sin^230°+2sin^260°+tan45°-tan60°+cos^230°=

sin^230°+2sin^260°+tan45°-tan60°+cos^230°=
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