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Question-30120




Question Number 30120 by ajfour last updated on 16/Feb/18
Commented by ajfour last updated on 16/Feb/18
Determine 𝛒, 𝛈, 𝛔, 𝛆   in terms  of 𝛌 and 𝛍 .
Determine\boldsymbolρ,\boldsymbolη,\boldsymbolσ,\boldsymbolϵintermsof\boldsymbolλand\boldsymbolμ.
Answered by mrW2 last updated on 17/Feb/18
Commented by ajfour last updated on 17/Feb/18
Thank you Sir. I have solved  the vector way.
ThankyouSir.Ihavesolvedthevectorway.
Commented by mrW2 last updated on 17/Feb/18
maybe one can use vector method to  get the result more easily.
maybeonecanusevectormethodtogettheresultmoreeasily.
Commented by mrW2 last updated on 17/Feb/18
let AB=c, BC=a, ∠ABC=θ  B(0,0)  D(λa,0)  C(a,0)  F(μc cos θ,μc sin θ)  A(c cos θ,c sin θ)    Eqn. of CF:  ((y−0)/(x−a))=((μc sin θ−0)/(μc cos θ−a))  y(μc cos θ−a)=(x−a)μc sin θ  Eqn. of AD  ((y−0)/(x−λa))=((c sin θ−0)/(c cos θ−λa))  y(c cos θ−λa)=(x−λa)c sin θ  Point G:  y_G (μc cos θ−a)=(x_G −a)μc sin θ  y_G (c cos θ−λa)=(x_G −λa)c sin θ  ⇒((μc cos θ−a)/(c cos θ−λa))=(((x_G −a)μ)/(x_G −λa))  ⇒(μc cos θ −a)x_G −λμac cos θ+λa^2 =(μc cos θ−λμa)x_G −μac cos θ+λμa^2   ⇒(1−λμ)x_G =(1−λ)μc cos θ+λ(1−μ)a  ⇒x_G =(((1−λ)μc cos θ+λ(1−μ)a)/(1−λμ))  ⇒y_G =((c sin θ(x_G −λa))/(c cos θ−λa))  ⇒y_G =((c sin θ)/(c cos θ−λa))×[(((1−λ)μc cos θ+λ(1−μ)a−λa(1−λμ))/(1−λμ))]  ⇒y_G =(((1−λ)μc sin θ)/(1−λμ))    Eqn. of BE:  (y/x)=((((1−λ)μc sin θ)/(1−λμ))/(((1−λ)μc cos θ+λ(1−μ)a)/(1−λμ)))=(((1−λ)μc sin θ)/((1−λ)μc cos θ+λ(1−μ)a))  y[(1−λ)μc cos θ+λ(1−μ)a]=x(1−λ)μc sin θ  Eqn. of AC:  ((y−0)/(x−a))=((c sin θ−0)/(c cos θ−a))  y(c cos θ−a)=(x−a)c sin θ  Point E:  y_E [(1−λ)μc cos θ+λ(1−μ)a]=x_E (1−λ)μc sin θ  y_E (c cos θ−a)=(x_E −a)c sin θ  ⇒(((1−λ)μc cos θ+λ(1−μ)a)/(c cos θ−a))=((x_E (1−λ)μ)/(x_E −a))  [(1−λ)μc cos θ+λ(1−μ)a]x_E −a[(1−λ)μc cos θ+λ(1−μ)a]=(1−λ)μ(c cos θ−a)x_E   [(1−λ)μa+λ(1−μ)a]x_E =a[(1−λ)μc cos θ+λ(1−μ)a]  [λ+μ(1−2λ)]x_E =(1−λ)μc cos θ+λ(1−μ)a  ⇒x_E =(((1−λ)μc cos θ+λ(1−μ)a)/(λ+μ(1−2λ)))  ⇒y_E =((c sin θ(x_E −a))/(c cos θ−a))=((c sin θ)/(c cos θ−a))×[(((1−λ)μc cos θ+λ(1−μ)a−aλ−aμ(1−2λ))/(λ+μ(1−2λ)))]  ⇒y_E =((c sin θ)/(c cos θ−a))×[(((1−λ)μ(c cos θ−a))/(λ+μ(1−2λ)))]  ⇒y_E =(((1−λ)μc sin θ)/(λ+μ(1−2λ)))    η=(x_G /x_E )=(((1−λ)μc cos θ+λ(1−μ)a)/(1−λμ))×((λ+μ(1−2λ))/((1−λ)μc cos θ+λ(1−μ)a))  ⇒η=((λ+μ(1−2λ))/(1−λμ))=((λ+μ−2λμ)/(1−λμ))   ...(I)  ε=(y_E /y_A )=(((1−λ)μc sin θ)/(λ+μ(1−2λ)))×(1/(c sin θ))  ⇒ε=(((1−λ)μ)/(λ+μ(1−2λ)))=((μ−λμ)/(λ+μ−2λμ))    ...(II)    using these two relations all other  values can be determined.  σ=((ε+(1−λ)(1−2ε))/(1−ε(1−λ)))  σ=(((((1−λ)μ)/(λ+μ(1−2λ)))+(1−λ)(1−((2(1−λ)μ)/(λ+μ(1−2λ)))))/(1−(((1−λ)μ)/(λ+μ(1−2λ)))(1−λ)))  σ=(((1−λ)μ+(1−λ)[λ+μ(1−2λ)−2(1−λ)μ])/(λ+μ(1−2λ)−(1−λ)^2 μ))  ⇒σ=((1−λ)/(1−λμ))    ρ=(((1−μ)+(1−ε)[1−2(1−μ)])/(1−(1−μ)(1−ε)))  ρ=(((1−μ)+[1−(((1−λ)μ)/(λ+μ(1−2λ)))][1−2(1−μ)])/(1−(1−μ)[1−(((1−λ)μ)/(λ+μ(1−2λ)))]))  ρ=(((1−μ)[λ+μ(1−2λ)]+[λ+μ(1−2λ)−(1−λ)μ][1−2(1−μ)])/(λ+μ(1−2λ)−(1−μ)[λ+μ(1−2λ)−(1−λ)μ]))  ⇒ρ=((1−μ)/(1−λμ))
letAB=c,BC=a,ABC=θB(0,0)D(λa,0)C(a,0)F(μccosθ,μcsinθ)A(ccosθ,csinθ)Eqn.ofCF:y0xa=μcsinθ0μccosθay(μccosθa)=(xa)μcsinθEqn.ofADy0xλa=csinθ0ccosθλay(ccosθλa)=(xλa)csinθPointG:yG(μccosθa)=(xGa)μcsinθyG(ccosθλa)=(xGλa)csinθμccosθaccosθλa=(xGa)μxGλa(μccosθa)xGλμaccosθ+λa2=(μccosθλμa)xGμaccosθ+λμa2(1λμ)xG=(1λ)μccosθ+λ(1μ)axG=(1λ)μccosθ+λ(1μ)a1λμyG=csinθ(xGλa)ccosθλayG=csinθccosθλa×[(1λ)μccosθ+λ(1μ)aλa(1λμ)1λμ]yG=(1λ)μcsinθ1λμEqn.ofBE:yx=(1λ)μcsinθ1λμ(1λ)μccosθ+λ(1μ)a1λμ=(1λ)μcsinθ(1λ)μccosθ+λ(1μ)ay[(1λ)μccosθ+λ(1μ)a]=x(1λ)μcsinθEqn.ofAC:y0xa=csinθ0ccosθay(ccosθa)=(xa)csinθPointE:yE[(1λ)μccosθ+λ(1μ)a]=xE(1λ)μcsinθyE(ccosθa)=(xEa)csinθ(1λ)μccosθ+λ(1μ)accosθa=xE(1λ)μxEa[(1λ)μccosθ+λ(1μ)a]xEa[(1λ)μccosθ+λ(1μ)a]=(1λ)μ(ccosθa)xE[(1λ)μa+λ(1μ)a]xE=a[(1λ)μccosθ+λ(1μ)a][λ+μ(12λ)]xE=(1λ)μccosθ+λ(1μ)axE=(1λ)μccosθ+λ(1μ)aλ+μ(12λ)yE=csinθ(xEa)ccosθa=csinθccosθa×[(1λ)μccosθ+λ(1μ)aaλaμ(12λ)λ+μ(12λ)]yE=csinθccosθa×[(1λ)μ(ccosθa)λ+μ(12λ)]yE=(1λ)μcsinθλ+μ(12λ)η=xGxE=(1λ)μccosθ+λ(1μ)a1λμ×λ+μ(12λ)(1λ)μccosθ+λ(1μ)aη=λ+μ(12λ)1λμ=λ+μ2λμ1λμ(I)ε=yEyA=(1λ)μcsinθλ+μ(12λ)×1csinθε=(1λ)μλ+μ(12λ)=μλμλ+μ2λμ(II)usingthesetworelationsallothervaluescanbedetermined.σ=ε+(1λ)(12ε)1ε(1λ)σ=(1λ)μλ+μ(12λ)+(1λ)(12(1λ)μλ+μ(12λ))1(1λ)μλ+μ(12λ)(1λ)σ=(1λ)μ+(1λ)[λ+μ(12λ)2(1λ)μ]λ+μ(12λ)(1λ)2μσ=1λ1λμρ=(1μ)+(1ε)[12(1μ)]1(1μ)(1ε)ρ=(1μ)+[1(1λ)μλ+μ(12λ)][12(1μ)]1(1μ)[1(1λ)μλ+μ(12λ)]ρ=(1μ)[λ+μ(12λ)]+[λ+μ(12λ)(1λ)μ][12(1μ)]λ+μ(12λ)(1μ)[λ+μ(12λ)(1λ)μ]ρ=1μ1λμ
Answered by ajfour last updated on 17/Feb/18
let  B be origin,  BC^(−)  = a^�   ,BA^(−)  = c^�  ,  CA^(−)  = b^�  = c^� −a^�   BG^(−)  =ρ(λa^� )+(1−ρ)c^�           =(1−σ)a^� +σ(μc^� )          = η(a^� +εb^� ) =η[a^� +ε(c^� −a^� )]  coeff. of a^�  is       λρ =1−σ = η−εη    ...(i)  coeff. of c^�  is       (1−ρ)=σμ = ηε       ...(ii)  ⇒   1−ρ = (1−λρ)μ         𝛒 = ((1−𝛍)/(1−𝛌𝛍))        σ=1−λρ = 1−(((λ−λμ)/(1−λμ)))     ⇒   𝛔 = ((1−𝛌)/(1−𝛌𝛍))    adding (i) and (ii)     η = λρ+(1−ρ)         =1−(1−λ)ρ         = 1−(((1−λ)(1−μ))/(1−λμ))       𝛈 = ((𝛍(1−𝛌)+𝛌(1−𝛍))/(1−𝛌𝛍))    ε = ((1−ρ)/η)     = [1−(((1−μ)/(1−λμ)))]×((1−λμ)/(μ(1−λ)+λ(1−μ)))        𝛆 = ((𝛍(1−𝛌))/(𝛍(1−𝛌)+𝛌(1−𝛍)))  .
letBbeorigin,BC=a¯,BA=c¯,CA=b¯=c¯a¯BG=ρ(λa¯)+(1ρ)c¯=(1σ)a¯+σ(μc¯)=η(a¯+ϵb¯)=η[a¯+ϵ(c¯a¯)]coeff.ofa¯isλρ=1σ=ηϵη(i)coeff.ofc¯is(1ρ)=σμ=ηϵ(ii)1ρ=(1λρ)μ\boldsymbolρ=1\boldsymbolμ1\boldsymbolλμσ=1λρ=1(λλμ1λμ)\boldsymbolσ=1\boldsymbolλ1\boldsymbolλμadding(i)and(ii)η=λρ+(1ρ)=1(1λ)ρ=1(1λ)(1μ)1λμ\boldsymbolη=\boldsymbolμ(1\boldsymbolλ)+\boldsymbolλ(1\boldsymbolμ)1\boldsymbolλμϵ=1ρη=[1(1μ1λμ)]×1λμμ(1λ)+λ(1μ)\boldsymbolϵ=\boldsymbolμ(1\boldsymbolλ)\boldsymbolμ(1\boldsymbolλ)+\boldsymbolλ(1\boldsymbolμ).
Commented by mrW2 last updated on 17/Feb/18
That′s really clearly laid out! Thanks sir!
Thatsreallyclearlylaidout!Thankssir!Thatsreallyclearlylaidout!Thankssir!

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