高中三角函数cos20cos40cos80=?

相关推荐

• 高中化学具体有几个定律呢?比如：质量守恒定律,还有?
• 谁有高中化学定律大全
• 高中英语有分~My topic of today is "Early Money"哪错了?说下原因!这个是短文改错,不能换位置哦!原因要说请错,好的话可以加分!
• 高中英语（有分）改错,只有一个是对的.You know how pleased it is to receive a letter from a 1.____ friend of yours,and how much eagerly you open and 2.____ read it.Reading friendly letters are always an enjoyable 3.____ thing.As a matter of a fact,it is a way to visit those 4.____ friends and places which we usually can not talk with 5.____ and see them every day.When writing a letter,think 6.____ about the person to whom you are writing.What would 7.____ he like to kno
• 高中英语单选一道It was about 600 years ago _______ the first clock with a face and an hour hand was made.A.thatB.untilC.beforeD.when老师上课讲是强调句,用that.但是我觉得填when的话,也可以啊……在此请教,望讲明白一些...一楼大哥,别光填一个选项啊,..
• 一个很难的高中英语单选题----高手帮忙In my opinion, life in the twenty-first century is much easier than _____ .A：that used to be B：it is used to C：it was used to D：it used to be答案是D,但是我看不懂D项,it是代指life的对吗?重点说一下it used to be 后面是不是省略了东西?如果是完整的,我怎么也理解不了,怎么可能以be结尾呢?
• 一道很难的高中英语单选题--------------务必高手帮忙28、The man in the lead swung his right arm _____ a signal for us to stop.A：as if to make    B：even if to make    C：as though making    D：even though making1、请选出答案并解释原因；2、请帮忙标准翻译.
• 已知X2+Y2-2X-4Y-4=0 求X+Y的取值范围要利用三角函数来做
• 能提高高中英语单选的好方法我现在是高二,完型,阅读都还可以,但就是单选做的特恶心,15道就错8道那种,请大侠们帮帮忙啊
• 高中英语一道单选Nobody knows ________broke into the house last night and stole the important papers A.who was it that B.it was who that C.who it was that D.that it was who 于是完全分不清啊啊.选C,为什么其他三个不行,另外这是一个什么句?B 和D为什么不行
• no longer,not any longer,no more,not any more 区别
• no 和without都可表示没有,那有什么区别呢?如题without是什么词>是介词还是副词?真的很难判断