ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D...

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ege let B base be a nice subset of R let D cone in 1133 with base B on Xy plaice 0,99 a y X B Oz How to find volume of D Vol ArealBz 07 Answer by concept of Riemann sum and this figure Vol Soh Area de By similarity ratio of height that I E ratio of the area Area AreaTBE C EJ Vol 5 Soh CI 5 Areal B At Sohc Ejaz Area Is Area B Check

Transcript of ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D...

Page 1: ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D cone in1133 with base B on Xy plaice 0,99 a y X B Oz Howtofindvolumeof D Vol ArealBz

ege let B base be a nice subset of R

let D cone in 1133 with base B on Xy plaice0,99

ay

X B Oz

Howtofindvolume of D Vol ArealBz 07

Answer by conceptof Riemann sum and this figure

Vol Soh Area de

By similarity ratio ofheight that I Eratio of the area

AreaAreaTBECEJ

Vol 5 SohCI 5ArealB At

Sohc Ejaz Area

IsAreaB Check

Page 2: ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D cone in1133 with base B on Xy plaice 0,99 a y X B Oz Howtofindvolumeof D Vol ArealBz

Cylindrical Coordinates at1133 itCr 0,21

Bo _polarcoordinates for r

the y plane µc yp crosgraagz

820

z rectangular vertical I 9coordinates t x y oX 11

Then a point P ix y z can becrosorseioso

represented by 18,0 where

I X rose

y rsinoz Z

And Cr z is called the atmdri as forIRS

Remarki cc is a constant n

KC c o describes a cylinder

µ uso c describes a fitI 4r ci sz c descries a horizontalplane i

I 1as inrectangular coordinates iz

Remake Wecan define cylindrical Xcoordinates in other directors y

h d

egi x x xi O c

1

Page 3: ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D cone in1133 with base B on Xy plaice 0,99 a y X B Oz Howtofindvolumeof D Vol ArealBz

Volumneelement

dV dxdydzrTirdotaz

orderofthe integration canbe changed L

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egI seealsoegatFindthe volume of the

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it

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Voeux f JeffgFrdzdrdof fo rut E drdo check

Page 4: ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D cone in1133 with base B on Xy plaice 0,99 a y X B Oz Howtofindvolumeof D Vol ArealBz

Spherical coordinates in IR ta quay f rho

g 4,0 where gasol ii

ig distance from theorigin geo

to angle from the pantier

Z axis to optOf loECT

A anglefrom cylindrical coordinates0 EOE 2T

Remark If Cr 0,7 is the cylindrical coordinates of E

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goodIn particular z2 r2 p2

Then

iyX rest paisfosoy raise f singserifz z piesof

rectangular spherical

cylindrical

Remardi If c is aconstant then

g c c o describes a sphereofradio c describes a halfplane vertical

of C describes

Page 5: ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D cone in1133 with base B on Xy plaice 0,99 a y X B Oz Howtofindvolumeof D Vol ArealBz

we 7 axis if 0

if ITI u mi

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e 4 is thepolarof 1Fr

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C f Eye Cone

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into x y't Cz 15 1

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Page 6: ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D cone in1133 with base B on Xy plaice 0,99 a y X B Oz Howtofindvolumeof D Vol ArealBz

p2sing t p654 2pm0 1 1

p spoof O

ie f p zoo o togetherwith Peoof zca f o is apointonly

c sub the formula into 7 5 27

gasof greig sie xi yt F pki.to970 050 Arioso

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Volume of ice creamcare againin spherical coordinates

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Sod The ice cream cone I is given byO E f ETOE OfE Is don'tmissthisOef ENT

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mucheasierthan cylindrical do Sottsingdol Steady Is check

Page 7: ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D cone in1133 with base B on Xy plaice 0,99 a y X B Oz Howtofindvolumeof D Vol ArealBz

ease fix y yf f if exists 9 03

0 If CXy D 90,0

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f at one point doesn't affectthe du

let D unit ball centered at aigui intersecting with theO loist octant

µ EThen D can berepresentedinspherical coordinates N

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If we want to calculate the average off over D

Page 8: ege B be nice of D B Xy plaice a - CUHK Mathematics...ege let B base be a nice subset of R let D cone in1133 with base B on Xy plaice 0,99 a y X B Oz Howtofindvolumeof D Vol ArealBz

we need to calculate Vol D too

In our case VoeCD f Vol unitsphere t IIHence

average off overD SIfCxisz2dVt

age Improper integrals

let fairy f yzz IT9 9 µ p

mbmtd

over unit ball B Kp4 A OffEl's

d Does lesion this Adv exist

where Be ftp 0 oJ oEpEE

dis Does fujio qescxis.edu exist