[數撚圍爐區] What is Mathematics? (4)

1001 回覆
26 Like 4 Dislike
2018-12-02 19:54:01
2018-12-02 19:57:56
有無數佬可以講下咩係dot cross product ,唔係好明個原理
2018-12-02 20:02:38
2018-12-02 20:03:11
2018-12-02 20:03:53
原理?
定你想問個"product"有咩意義?
2018-12-02 20:04:37
係呀 唔係好明
2018-12-02 20:05:16
2018-12-02 20:06:32
中學雞的講法係
dot product measures angles
cross product measures area
2018-12-02 20:07:04
2018-12-02 20:07:46
唔係中學雞講法呢
2018-12-02 20:08:56

2018-12-02 20:14:30
wedge product 係generalisation of areas and volume (cross product係wedge product一個特殊case ge Hodge dual)
inner product 係generalisation of dot product (都係measuring of angles)
希望無記錯, 有錯任插
2018-12-02 20:17:36
btw cross product得R^3同R^7先define到
2018-12-02 20:35:22
2018-12-02 20:46:12
2018-12-02 20:49:22
好接受唔到有啲人/書教(a,b)×(c,d)=(0,0,ad-bc)
2018-12-02 20:56:50
如果將R^2 embed 落 R^3
我唔記得左係R^n take個"cross product"會飛左去邊 淨係記得係 3同7 先會落番個自己度
2018-12-02 21:43:41
係咪related to the fact that only dimension 1248先有division algebra
corresponds to R C H O

如果用你前面個metric再wedge再hodge dual再metric既角度睇
R^7 整完都係一個5 vector咋喎
2018-12-03 01:43:25
2018-12-03 02:33:34
share 佢啲notes 黎睇下,好奇想知佢教咩
2018-12-03 03:37:46

2018-12-03 07:58:26
2018-12-03 07:59:03
2018-12-03 08:11:16
[member]主要take complement或者take convergent sequence[
至於用邊個要執生/member]
2018-12-03 09:28:31


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