应《网络安全法》要求，自2017年10月1日起，未进行实名认证将不得使用互联网跟帖服务。为保障您的帐号能够正常使用，请尽快对帐号进行手机号验证，感谢您的理解与支持！

24小时热门版块排行榜    

小木虫论坛-学术科研互动平台 » 专业学科区 » 数学 » 基础数学 » 小女子公式求助，各位大神帮帮啦！
101/1返回列表
查看: 1719  |  回复: 9
只看楼主 @他人 存档 新回复提醒 (忽略) 收藏    在APP中查看

追风的风

新虫 (小有名气)

[求助] 小女子公式求助，各位大神帮帮啦！ 已有3人参与

我有一个公式，需要求出x，s=2R*sin（x/2）+p*tan(x/2),各位大神这个该怎么求，谢啦！（s，R，p当做已知）
回复此楼

» 猜你喜欢
哈哈
1楼 2016-01-21 09:57:08
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

wurongjun

专家顾问 (职业作家)

【答案】应助回帖

★ ★
感谢参与，应助指数 +1
追风的风(Edstrayer代发): 金币+2 2016-01-24 03:37:32
Matlab 的solve命令!
例如!
>> solve('2*sin(x/2)+3*tan(x/2)=2','x')

ans =

[      2*atan((2/3*(-3/4+1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+1/4*((6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)-9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))^3+(-3/4+1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+1/4*((6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)-9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))^2-1)/(-3/4+1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+1/4*((6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)-9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2)))]
[ 2*atan((2/3*(-3/4+1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-1/4*((6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)-9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))^3+(-3/4+1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-1/4*((6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)-9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))^2-1)/(-3/4+1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-1/4*((6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)-9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2)))-2*pi]
[ 2*atan(2/3*(-3/4-1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+1/4*i*((-6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)+9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))^3+(-3/4-1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+1/4*i*((-6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)+9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))^2-1,-3/4-1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+1/4*i*((-6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)+9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))]
[ 2*atan(2/3*(-3/4-1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-1/4*i*((-6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)+9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))^3+(-3/4-1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-1/4*i*((-6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)+9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))^2-1,-3/4-1/4*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)-1/4*i*((-6*(315+72*19^(1/2))^(1/3)*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)*(315+72*19^(1/2))^(2/3)+9*(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2)+48*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3)/(((315+72*19^(1/2))^(2/3)+9+3*(315+72*19^(1/2))^(1/3))/(315+72*19^(1/2))^(1/3))^(1/2))^(1/2))]

>> double(ans)

ans =

   0.7824         
  -4.5525         
   5.0266 - 2.6622i
   5.0266 + 2.6622i
赞一下(4人) 回复此楼
善恶到头终有报,人间正道是沧桑.
2楼2016-01-21 10:20:33
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

liuqh

铁杆木虫 (正式写手)

【答案】应助回帖

★
感谢参与，应助指数 +1
追风的风(Edstrayer代发): 金币+1 2016-01-24 03:37:43
将sin(x/2)用tan(x/2)表示后，化简可得一个四次方程，有解析解
赞一下 回复此楼
3楼2016-01-21 10:38:24
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

laosam280

禁虫 (正式写手)
★ ★
感谢参与，应助指数 +1
追风的风(Edstrayer代发): 金币+2 2016-01-24 03:37:12
本帖内容被屏蔽
4楼2016-01-21 13:27:30
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

追风的风

新虫 (小有名气)
引用回帖:
2楼: Originally posted by wurongjun at 2016-01-21 10:20:33
Matlab 的solve命令!
例如!
>> solve('2*sin(x/2)+3*tan(x/2)=2','x')

ans =






>> double(ans)

ans =

   0.7824         
  -4.5525         
   5.0266 - 2.6622i
   5 ...

可不可以结果出现R,s,p啊
赞一下 回复此楼
哈哈
5楼2016-01-24 11:35:16
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

w-chin

木虫 (正式写手)
这个可借助mathematica给出解析解的，但结果超复杂，这里没法全部粘贴出来...
试一下这个命令就可以看出结果了Solve[2 R Sin[x/2] + p Tan[x/2] == s, x]
赞一下 回复此楼
井蛙不可以语于海者，拘于虚也；夏虫不可以语于冰者，笃于时也；曲士不可以语于道者，束于教也。
6楼2016-01-24 12:42:45
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

w-chin

木虫 (正式写手)
结果文件这里，没法直接copy出来。话说为什么要解析解？http://pan.baidu.com/s/1i4zY14h
赞一下 回复此楼
井蛙不可以语于海者，拘于虚也；夏虫不可以语于冰者，笃于时也；曲士不可以语于道者，束于教也。
7楼2016-01-24 12:50:17
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

w-chin

木虫 (正式写手)
结果是nb格式，mathematica文件格式
赞一下 回复此楼
井蛙不可以语于海者，拘于虚也；夏虫不可以语于冰者，笃于时也；曲士不可以语于道者，束于教也。
8楼2016-01-24 12:51:27
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

追风的风

新虫 (小有名气)
引用回帖:
7楼: Originally posted by w-chin at 2016-01-24 12:50:17
结果文件这里，没法直接copy出来。话说为什么要解析解？http://pan.baidu.com/s/1i4zY14h

我有另外一个公式，-t/（2Rθ）<=x2<=t/（2Rθ），我需要让我们s=2R*sin（x/2）+p*tan(x/2)的x>=x2，做出优化，优化p，使p小一些，这样怎么办啊？大神
赞一下 回复此楼
哈哈
9楼2016-01-24 14:58:01
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

wurongjun

专家顾问 (职业作家)
引用回帖:
5楼: Originally posted by 追风的风 at 2016-01-24 11:35:16
可不可以结果出现R,s,p啊...

不行!你说的那个叫解析解!
这个问题似乎只能求数值解!
赞一下 回复此楼
善恶到头终有报,人间正道是沧桑.
10楼2016-01-24 17:54:21
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 追风的风 的主题更新
101/1返回列表
普通表情 龙 兔 虎 猫
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[基金申请] 估计是周四 +4 archvillain 2026-08-18 4/200 2026-08-24 13:53 by zzuzxg
[基金申请] 2026国自然函评费到账 +17 羊腰板 2026-08-21 18/900 2026-08-24 12:03 by iaeyuan
[基金申请] 建议基金发布提前给出明确的时间点 +12 kulium 2026-08-21 15/750 2026-08-24 12:02 by iaeyuan
[基金申请] 范进中举一文的中心思想 +6 炎黄贵胄 2026-08-22 7/350 2026-08-24 11:58 by 6543yes
[基金申请] 朋友圈看到的 +7 wangzilk 2026-08-18 9/450 2026-08-24 10:50 by cmrandy
[基金申请] 放榜前的不淡定 20+4 snowwithsea 2026-08-19 17/850 2026-08-24 10:20 by echo8914667
[基金申请] 科研孤儿太难了 +18 我4大白菜 2026-08-20 19/950 2026-08-24 09:47 by 凯恩广盛催化分�
[基金申请] 明天应该可查了！？ +4 chengyan1220 2026-08-23 4/200 2026-08-24 08:47 by gloomy6159
[基金申请] 什么时候开奖？ +10 CrisMessi 2026-08-18 11/550 2026-08-24 06:50 by 开心的小狮子
[基金申请] 2026年的国家社科基金项目通讯评审的新规则与新动向、新挑战 +4 process2012 2026-08-23 5/250 2026-08-23 19:58 by jurkat.1640
[基金申请] 今天放榜吗？ +15 布布和一二 2026-08-19 16/800 2026-08-23 09:55 by 张春生
[基金申请] 只有每年这种时候来逛逛小木虫 +24 yaoyewhu2008 2026-08-20 26/1300 2026-08-22 17:43 by kammury
[基金申请] filecode，4个jtjc了 +13 ziyangfang 2026-08-19 16/800 2026-08-22 17:08 by WH3796
[基金申请] 看来今天不会放榜了？ +8 chengyan1220 2026-08-21 11/550 2026-08-21 17:52 by dcqxinyang
[基金申请] 应该是下周三26日公布了吧？ +4 哈哈蛤？ 2026-08-21 4/200 2026-08-21 10:58 by Vivilian
[论文投稿] 投稿咨询 +5 wwm09 2026-08-17 7/350 2026-08-21 10:11 by 期刊论文帮手
[基金申请] 今天放榜没戏了吧 +9 yuleib84 2026-08-19 11/550 2026-08-21 10:06 by gltch
[基金申请] 重要消息，中午系统在维护 +11 yuleib84 2026-08-18 12/600 2026-08-20 11:09 by xskun
[基金申请] 明天放榜？ +5 Shxjjxjkx 2026-08-18 5/250 2026-08-18 18:14 by -大大大大大-
[基金申请] 今天维护系统维护 祝所有人 高中 +8 gjjjzhong 2026-08-18 9/450 2026-08-18 13:01 by 家与远方
信息提示
关闭
请填处理意见
关闭