有數唔識做...@@"

oscar

真係玩死我...
呢題數陪伴著我2粒鐘....

細薯

Originally posted by oscar at 2005-3-30 07:56 PM:
真係玩死我...
呢題數陪伴著我2粒鐘....

不
是 (b) part......XDXD

oscar

Originally posted by smallpotato226 at 2005-3-30 19:57:

不
是 (b) part......XDXD

有時做數就是那麼無奈....

細薯

Originally posted by oscar at 2005-3-30 07:58 PM:

有時做數就是那麼無奈....

我都試過........

http://www.xanga.com/home.aspx?user=LWrabbit
Wednesday, March 23, 2005

Question

In triangle ABC, let a/sinA=b/sinB=c/sinC=k,where A,B and C are interior angles.

(a)show that a/sinA=a+b+c/sinA+sinB+sinC
(b)略
(c)略

my answer

i divide it into two part......
=======================
a+b+c=k(sinA+sinB+sinC)
=======================
sinA+sinB+sinC=(a+b+c)/2
=======================
therefore
a+b+c / sinA+sinB+sinC =k^2(sinA+sinB+sinC) / k(sinA+sinB+sinC)
                                 =k
therefore = a /sin A

answer

a+b+c / sinA+sinB+sinC = k(sinA+sinB+sinC) / sinA+sinB+sinC  = k = sin A

.................

[ Last edited by smallpotato226 on 2005-3-30 at 08:07 PM ]