若cotx/(2cosx+1)=1,则cos2x的值为sin2x=(√5-1)/2cos2x怎么会等于1-√3/2 怎么不回话?我解出来cox2x=√(√5-1)/2 约等于0.786但备选答案没一个对的,怎么办?备选答案是A.3/5 B.-3/5 C.(2根号5)/5 D.-(2根号5)/
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/02 20:34:50
![若cotx/(2cosx+1)=1,则cos2x的值为sin2x=(√5-1)/2cos2x怎么会等于1-√3/2 怎么不回话?我解出来cox2x=√(√5-1)/2 约等于0.786但备选答案没一个对的,怎么办?备选答案是A.3/5 B.-3/5 C.(2根号5)/5 D.-(2根号5)/](/uploads/image/z/5532693-69-3.jpg?t=%E8%8B%A5cotx%2F%282cosx%2B1%29%3D1%2C%E5%88%99cos2x%E7%9A%84%E5%80%BC%E4%B8%BAsin2x%3D%28%E2%88%9A5-1%29%2F2cos2x%E6%80%8E%E4%B9%88%E4%BC%9A%E7%AD%89%E4%BA%8E1-%E2%88%9A3%2F2+%E6%80%8E%E4%B9%88%E4%B8%8D%E5%9B%9E%E8%AF%9D%EF%BC%9F%E6%88%91%E8%A7%A3%E5%87%BA%E6%9D%A5cox2x%3D%E2%88%9A%EF%BC%88%E2%88%9A5-1%29%2F2+%E7%BA%A6%E7%AD%89%E4%BA%8E0.786%E4%BD%86%E5%A4%87%E9%80%89%E7%AD%94%E6%A1%88%E6%B2%A1%E4%B8%80%E4%B8%AA%E5%AF%B9%E7%9A%84%EF%BC%8C%E6%80%8E%E4%B9%88%E5%8A%9E%EF%BC%9F%E5%A4%87%E9%80%89%E7%AD%94%E6%A1%88%E6%98%AFA.3%2F5+B.-3%2F5+C.%282%E6%A0%B9%E5%8F%B75%29%2F5+D.-%282%E6%A0%B9%E5%8F%B75%29%2F)
xrP_Iu0stFr2E[B;϶RjeL!!w{nW(8u+?wOT/W
YPWFLJ*6tIXU
]fUfqkE8EEDFB}
mN}j#9,U/9'ʢ}r{ezhC2064qxx7"%9y,$R?E$Ef?`4|G$,N\X?Ia
>pXZ9%ȿC{Q6d;Mg͌&l8'6efM-"Y-ƞ/[+uɰM?gpq0aȽcϵBFM^m?zeUD