Sloving Equation

2006-11-26 10:31 pm
Ta sin 30* =Tb sin 60* .....................(1)
Ta cos 30* + Tb cos 60* =100 ...........(2)

Find Ta and Tb

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更新1:

另有 Ta COS 30* =Tb COS 15* .....................(1) Ta SIN 30* + Tb SIN 15* =800 ...........(2)

回答 (2)

2006-11-27 2:21 am
✔ 最佳答案
其實要solve這個要知道sin 30,cos 15等等全部都是實數來的。30、60這些是特別角,可以用很簡單的根式表示出來,所以solve這個應該不太難。

Ta sin 30* =Tb sin 60* .....................(1)
Ta cos 30* + Tb cos 60* =100 ...........(2)

Ta /2 =Tb (√3/2) .....................(1)
Ta (√3/2) + Tb /2 =100 ...........(2)

Ta =Tb √3
Ta √3 + Tb =200

Ta =Tb √3
Tb √3 √3 + Tb =200
4Tb=200
Tb=50
Ta=50√3
2006-11-26 11:02 pm
Ta sin 30* =Tb sin 60* .................... .(1)
Ta cos 30* + Tb cos 60* =100 ...........(2)

from (1)
Ta sin 30* =Tb sin 60*

a sin 30* =b sin 60*

1/2a=√3/2b or a=√3b
from (2)
Ta cos 30* + Tb cos 60* =100
Ta ( √3/2)+ Tb (1/2) =100
T(3/2)b+ Tb (1/2) =100
2Tb=100
Tb=50
Ta=50 √3


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