cos1°+cos2°+cos3°.+co180°=?
人气:256 ℃ 时间:2020-01-31 04:01:53
解答
注意到cos1+cos179=cos1+cos(180-1)=cos1-cos1=0一般地,有cosx+cos(180-x)=0因此cos1°+cos2°+cos3°.+cos180°=(cos1+cos179)+(cos2+cos178)+...+(cos89+cos91)+cos90+cos180=0+0+...+0+0+(-1)=-1
推荐
- cos1°+cos2°+cos3°+.+cos359°等于多少.
- cos1°+cos2°+cos3°+.+cos360°
- cos1/9π*cos2/9π*cos3/9π*cos4/9π=?怎么算?答案是1/16,
- cos1°+cos2°+cos3°+...+cos²89°
- 比大小cos1,cos2,cos3,cos4
- 如图所示,在三角形ABC中,AB=AC=5,AD为中线,AD=4,BC=6,点P是BC上的任意一点,求P点到两腰距离之和.
- 帮忙转换一下sin、cos、tan的度数
- Jim's mother asked him to go home right a____
猜你喜欢
- 1,Mike,bored,this morning,at home,was 2,they,so,were,happy,two days ago
- 一个了字下面一个口念什么?
- 天游峰的扫路人片段解答,嘉奖积分,急
- 英语翻译
- For _________ reasons,I will not be able to attend the meeting.(cebtain)
- I have visited Beijing.(改为一般疑问句,并作否定回答)
- 集气瓶内的水的作用
- My brother has two ( ) for dinner every evening.