gradients of function

2011-01-19 7:24 pm

我抩唔清why有時 \-/f 係normail to the curve (the graph of a vector-valued function r(t) in 2d or 3d),,有時又係tangent ,,For example,我做到有一題係話determine the path that shark will follow from one point to the origin ,the shark will detect the presence of blood in the water,個時要計\-/f,而\-/f 是tangent to the that path(max rate of change of direction)...搞到我好亂呀~!!~~~

更新1:

http://www.flickr.com/photos/11667399@N03/5369783017/

更新2:

有條問題,不過我真係好想搞清個CONCEPT..唔係只係知道個ANS~

更新3:

仲係唔係好明 1."This is equal to the normal vector at the point,normal in a sense that it is normal to the countour of equal concentration." 2."This vector is also the path of maximum rate of change ,so it is atangent of the shark's path." 係咪有得PROOF,,可唔可以PROOF 埋比我睇,THX

更新4:

equal係咪指佢地個value??

更新5:

1. 佢地唔係prependicular to each other 咩??