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Cross Product
Gousider wo co-erdlinale vectors
2 Ay at By
Ay Be
oan, te cross product 1S dolined! as:
as x yo 8
AxÂź Ă©= Ae Ay Ap
gx &y Be
A
= [AyBa- Ae) +4 (AeBx-Bad,) + 2(Adby- BAS) -Lt)
We con shox fuk Huis is rdotecl to ee angle betwen +00
Necls. by comsdahag Xa. Tollowng example:
«>
Evomples Let = A
Pe Py
= Besox + Sud 9
Us te deletmunont tule, colauloke x8
>
4
ond = RxA
A âA âA
a os x J z
Answes AxR = a Boe
Rees@ Burd ©
= O%4 Ott ARGin@
BrA = AB US F r
wis is an example of the niles
[ssl
Ax& = latlal sd | -(2)
a
os 3 so
AxR = - BxA -(3)
We Con we on algebraic apptaach. by nobng tab
Ax(B+?) = AR Axe
| ~(4)
ReQ = 2
A an
a= 6)
Bxk = 9
Exacise Using (4) ond (3) and He veckws dh the previous
example , shor ab
AXB © ABSinŸ
Calulus in Bree Pimensrous
In ordinary ome dimensicud calculus we aim to quant hy the
rade d, change, ot a funchan.
f,
'
Tuan At ng dé Caphwes ha dha of a deivative
Bx dx
Now for âwhnitesinel quonbhes We uk. df AF ate,
%
ot
a dx ax.
Tn tre dimensions, fwe ae seveal direchous in voile
a funckons rake dy inctease May be delemned.
= Qk oa of «A ot 4
[vt = > od âhe? - (8)
we owe
[a = oP ty - (2),
We con omve ot te gomchical reais
) Ae died of Tis papndicular to te
suslaces alowg vobich fis constent.
i) Te gradient TF pots due te clirechae in wold a Anchor
dactecses, most rapidly.
Hawuple « T(xy) = +2xy
a swhaces of = comstnt «fF ove hu perbodluc sheets
1 Jb § constant
| b
â4 ot pa
â_
âThan Vt a42ys +2x a, Late look ot Huis in thee xy
Pane.
34 5 cosh
Ă©
ee 1
Tuo gradient pants im he dutection ot steepest asconh
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