Originally posted by Sol_Campbell at 2005-3-18 09:09 PM:
所以咪話少野背,唔係冇野背囉:icon101:
arc length果d 公式我仲未記到:icon099:
我又唔覺得少喎:icon100:
Originally posted by Sol_Campbell at 2005-3-18 09:09 PM:
所以咪話少野背,唔係冇野背囉:icon101:
arc length果d 公式我仲未記到:icon099:
practice makes perfect:icon101:
Originally posted by kawai at 2005-3-18 09:13 PM:
我又唔覺得少喎:icon100: 積分好多:icon100:
Originally posted by Raul at 2005-3-18 09:07 PM:
好過bio啦:icon099:
chem:icon099::icon101:
Originally posted by 久違 at 2005-3-18 21:14:
chem:icon099::icon101:
192樣:icon099:
Originally posted by 久違 at 2005-3-18 09:14 PM:
chem:icon099::icon101:
都係inorg同org chem姐:icon074:
Originally posted by 久違 at 2005-3-18 08:59 PM:
不段做pape:icon090:
唔識都變識:icon101:
雖然past paper d solution睇得明
但返去做書o個D, 完全做唔到, 又冇solution係手
今日a.math section a題locus空晒, 題LQ避左,
做左trigo 3d, 又係唔識:icon075:
問數實際D.
有個圓x^2+y^2=1, 有一點variable pt P在圓外, M&N都在圓上
令PM同PN成為兩條tangent, 角MPN=90度
(a)part show PMON is square做到
(b)part find locus of P 就完全唔知點做
識既可否賜教, 我only想知做數個方向, 唔使答案:icon087:
Originally posted by 2076 at 2005-3-19 12:09 AM:
雖然past paper d solution睇得明
但返去做書o個D, 完全做唔到, 又冇solution係手
今日a.math section a題locus空晒, 題LQ避左,
做左trigo 3d, 又係唔識:icon075:
問數實際D.
識既可否賜教, 我only ... 你可以試下畫圖,睇下條locus係點再做會易d
因為係正方形,PO長度係root2
O (0,0)
let P(x,y)
(x-0)^2+(y-0)^2=2
x^2+y^2=2
應該係咁:icon101:
如果真係岩既話,我覺得呢類好似唔多見,
通常係x=一堆野,y又等於一堆野(好似話P係兩點既mid pt)
之後代下代下就搵到x,y既關係....唔識講:icon101:
一係你俾多條ex黎丫:icon101:
[ Last edited by Sol_Campbell on 19-3-2005 at 01:00 AM ]
Originally posted by Sol_Campbell at 2005-3-19 12:54 AM:
你可以試下畫圖,睇下條locus係點再做會易d
因為係正方形,PO長度係root2
O (0,0)
let P(x,y)
(x-0)^2+(y-0)^2=2
x^2+y^2=2
應該係咁:icon101:
如果真係岩既話,我覺得呢類好似唔多見,
通常係x=一堆野 ...
搵x,y既關係就得嫁啦:icon075::icon075::icon075:
Originally posted by Sol_Campbell at 2005-3-19 12:54 AM:
你可以試下畫圖,睇下條locus係點再做會易d
因為係正方形,PO長度係root2
O (0,0)
let P(x,y)
(x-0)^2+(y-0)^2=2
x^2+y^2=2
應該係咁:icon101:
如果真係岩既話,我覺得呢類好似唔多見,
通常係x=一堆野 ...
mo:icon099::icon101:
應該岩...唔洗驚:icon099::icon101:
[ Last edited by 久違 on 19-3-2005 at 02:27 AM ]
Originally posted by Sol_Campbell at 2005-3-19 12:54 AM:
你可以試下畫圖,睇下條locus係點再做會易d
因為係正方形,PO長度係root2
O (0,0)
let P(x,y)
(x-0)^2+(y-0)^2=2
x^2+y^2=2
應該係咁
如果真係岩既話,我覺得呢類好似唔多見,
通常係x=一堆野,y又等於一堆野(好似話P係兩點既mid pt)
之後代下代下就搵到x,y既關係....唔識講
一係你俾多條ex黎丫
原來係咁, 我個同學都一樣案, 唔該晒.
我靜係識做x同y in terms of t,
跟住find mid-pt or 畀個比例o個種
睇來可能真係要出去補補圓形,locus,同co-geo了:icon075:
Originally posted by Sol_Campbell at 2005-3-18 09:09 PM:
所以咪話少野背,唔係冇野背囉:icon101:
arc length果d 公式我仲未記到:icon099: arc length 唔好背啦...推出黎好好多
prove:assume 每一小段arc length為一個個直角三角形
then
integrate ds=integrate root(dx^2+dy^2)(pyth.thm)
抽dx=>s=integrate root(1+dy/dx^2)dx
抽dy=>s=integrate root(1+dx/dy^2)dy
抽dt=>s=integrate root(dx/dt^2+dy/dt^2)dt
:o
睇番原來我漏左integral sign:icon101:
同埋要加番upper limit& lower limit
[ Last edited by beckham312oo on 20-3-2005 at 05:11 PM ]
Originally posted by beckham312oo at 2005-3-19 10:03 AM:
arc length 唔好背啦...推出黎好好多
prove:assume 每一小段arc length為一個個直角三角形
then s=root(dx^2+dy^2)(pyth.thm)
抽dx=>s=root(1+dy/dx^2)dx
抽dy=>s=root(1+dx/dy^2 ...
有得推就唔同D:icon101:
不過Pure D時間好緊密
推唔推得切都成問題:icon099:
所以我like Physics多D
好多野好生活法
容易D搵方法去記
而且時間冇咁緊迫:icon101:
Originally posted by 麥旋風 at 2005-3-20 01:47 PM:
有得推就唔同D:icon101:
不過Pure D時間好緊密
推唔推得切都成問題:icon099:
所以我like Physics多D
好多野好生活法
容易D搵方法去記
而且時間冇咁緊迫:icon101: 不過phy 好多都係推出黎啦...
唔通真係會走去記 Y=Fl/Ax & k=YA/l o個d式咩:icon101:
不過又真係好推過pure 好多既
Originally posted by beckham312oo at 2005-3-20 05:11 PM:
不過phy 好多都係推出黎啦...
唔通真係會走去記 Y=Fl/Ax & k=YA/l o個d式咩:icon101:
不過又真係好推過pure 好多既
後面有嫁嘛:icon101:
Originally posted by 麥旋風 at 2005-3-20 01:47 PM:
有得推就唔同D:icon101:
不過Pure D時間好緊密
推唔推得切都成問題:icon099:
所以我like Physics多D
好多野好生活法
容易D搵方法去記
而且時間冇咁緊迫:icon101:
我覺得phy好似有乜野記咋喎
essay除外:icon101:
Originally posted by kawai at 2005-3-20 05:18 PM:
我覺得phy好似有乜野記咋喎
essay除外:icon101:
頂，唔計essay想點:icon101:
不過其實都有野記既
唔可以單靠睇後面
否則有多野唔識變通:icon110:
Originally posted by 麥旋風 at 2005-3-20 06:27 PM:
頂，唔計essay想點:icon101:
不過其實都有野記既
唔可以單靠睇後面
否則有多野唔識變通:icon110:
當然唔係完全冇啦:icon101:
thin film同extra structure d式就冇比:icon101:
Originally posted by 2076 at 2005-3-18 04:35 PM:
各位師兄: 其實Pure Maths難唔難讀架?
我依家中五, A Math成績一般, 有幾課仲好弱
例如見到"Locus"就例牌一片空白,
如果到中六, 讀Pure會唔會更加辛苦??:icon075::icon075:
讀就Add. Maths易
考就Pure Maths易
Originally posted by 天生射手 at 2005-3-22 12:49 PM:
讀就Add. Maths易
考就Pure Maths易
pure math d pastpaper真係...