中4 maths 神手快d入
suppose P(a,b) is a point on the straight line x-y+1=0 such that the sum of the distance between P and the point A(1,0) and distance between P and the point B(3,0) is the least,find the value of a+b.唔係幾明e條,最好可以解得易明d P is on the line: x-y+1=0 (y=x+1)
A=(1,0), B=(3,0)
find the coordinates of P such that the distance AP+BP is minimum 咁姐係點找 冇人理我= = 本帖最後由 火中有火 於 19-2-2012 01:47 編輯
(打果時冇睇到P(a,b),用左P(m,n))
之後...我剩係識d佢了...
但係一d就知唔係路...
交比電腦計 答案係
a=1/3 and b=4/3
a+b=5/3
↓AP+BP↓
↓d/dx(AP+BP)↓
結論:這是中四的題目嗎!?(定係你打錯題目:@) 本帖最後由 承b 於 20-2-2012 11:38 編輯
其實唔洗用徵積分/電腦都計到囉=.= 其實唔洗用徵積分/電腦都計到囉=.=
承b 發表於 20-2-2012 11:20 http://www.nakuz.com/bbs/images/common/back.gif
咁要掉返轉請你教路 本帖最後由 承b 於 21-2-2012 23:58 編輯
del~~~~~~~~~~~~~~~~~ 再做聯立方程就做到 再做聯立方程就做到
承b 發表於 20-2-2012 20:54 http://www.nakuz.com/bbs/images/common/back.gif
我輸得好徹底:'(...
頁:
[1]
2