中4 maths 神手快d入

承b

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

[H]bunbunbunbun

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

承b

咁姐係點找

承b

冇人理我= =

火中有火

(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)

承b

其實唔洗用徵積分/電腦都計到囉=.=

火中有火

其實唔洗用徵積分/電腦都計到囉=.=
承b 發表於 20-2-2012 11:20

    咁要掉返轉請你教路

承b

del~~~~~~~~~~~~~~~~~

承b

再做聯立方程就做到

火中有火

再做聯立方程就做到
承b 發表於 20-2-2012 20:54

    我輸得好徹底...