求值:(2cos80°+cos160°)/cos70°
来源:学生作业帮助网 编辑:六六作业网 时间:2024/09/09 03:40:14
求值:(2cos80°+cos160°)/cos70°求值:(2cos80°+cos160°)/cos70°求值:(2cos80°+cos160°)/cos70°cos160°+cos80°=cos(
求值:(2cos80°+cos160°)/cos70°
求值:(2cos80°+cos160°)/cos70°
求值:(2cos80°+cos160°)/cos70°
cos160° + cos80° = cos(120°+40°) + cos(120°-40°) = 2cos120°cos40° = -cos40°
cos80° - cos40° = cos(60°+20°) - cos(60°-20°) = -2sin60°sin20° = -2sin60°cos70°
所以(2cos80°+cos160°)/cos70° = -2sin60° = -根号3
求值:(2cos80°+cos160°)/cos70°
cos40°+cos60°+cos80°+cos160°怎样求值?
(2cos80°+cos160°)/cos70°
化简求值:cos10°*cos20°*cos40°*cos80°*cos160°
cos40°cos80°+cos80°cos160°+cos160°cos40°
求值cos40°cos80°+cos80°cos160°+cos160°cos40°我需要的是过程,老师说这类题是用积化和差公式,可是我还是弄不懂……
cos40×cos80×°cos160°为什么等于2sin40cos40cos80cos160/(2sin40)
cos40°+cos60°+cos80°+cos160°
cos40度乘cos80度乘cos160度 求值?麻烦大侠解答下
cos40+cos60+cos80+cos160怎么做?cos40+cos60+cos80+cos160
计算cos40+cos60+cos80+cos160.
化简 根号下[1-(sin160°)^2] A.cos160 B.-cos160 C.土cos160 D.无法确定
tan5°+1/tan5°-2/cos80° 化简求值
化简求值;(1-sin80°)/cos80°
化简((1+sinx)/cosx)*((sin2x)/(2cos平方((π/4)-(x/2))) 额 请大家认真看看吧还有一题 cos40°cos80°cos160°等于多少
怎样不通过求值判断大小,比如sin194°和cos160° 哪个大
设M=cos20°×cos40°×cos60°×cos80°×cos100°×cos120°×cos140°×cos160°,求证:M=1/256
化简根号1-2sin200°*cos160°