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Test for θ=20 and ϕ=0
Solving for the components of the ellipse
a1=2.53sin(θ)sin(115−θ)=2.53sin(20∘)sin(115∘−20∘)=2.53⋅.342.9962=.8686
a2=2.53sin(θ)sin(65−θ)=2.53sin(20∘)sin(65∘−20∘)=2.53⋅.342.0872=1.2237
cellipse≡(−Δa sin(65∘),0,z+Δa cos(65∘))
cellipse≡(−a2−a12sin(65∘),0,2.53+a2−a12cos(65∘))
cellipse≡(−1.2237−.86862sin(65∘),0,2.53+1.2237−.86862cos(65∘))
cellipse≡(−.35502sin(65∘),0,2.53+.35502cos(65∘))
cellipse≡(−.1775sin(65∘),0,2.53+.1775cos(65∘))
cellipse≡(−.1609,0,.0750)
P(ϕ=0)≡(−a2−a12sin(65∘)+a1+a22sin((65∘),0,2.53+a2−a12cos(65∘)−a1+a22cos(65∘))
P(ϕ=0)≡(−1.2234−.86842sin(65∘)+.8684+1.22342sin((65∘),0,2.53+1.2234−.86842cos(65∘)−.8684+1.22342cos(65∘))
P(ϕ=0)≡(−.35502sin(65∘)+2.09182sin((65∘),0,2.53+.35502cos(65∘)−2.09182cos(65∘))
P(ϕ=0)≡(−.1775sin(65∘)+1.0459sin((65∘),0,2.53+.1775cos(65∘)−1.0459cos(65∘))
P(ϕ=0)≡(.7870,0,2.1623)
x=2.53cos(ϕ)cot(θ)+cos(ϕ)cot(65∘)
x=2.53cos(0)cot(20∘)+cos(0)cot(65∘)
x=2.532.7475+.4663
x=2.533.2138=.7870cm
The y component is zero for ϕ=0
The z component can be found from the ellipse equation
z=−cot(65∘)x+2.53=−cot(65∘)(.7870)+2.53=2.1623 cm
e≡sin(25∘)cos(20∘)=0.96447
rD1=RLower Dandelincos(θ)=(ae−Δa)tan(65∘)cos(θ)rD2=RLower Dandelincos(θ)=(ae+Δa)tan(65∘)cos(θ)
rD1=(a1+a22e−a2−a12)tan(65∘)cos(θ)rD2=(a1+a22e+a2−a12)tan(65∘)cos(θ)
rD1=(.8686+1.22372e−1.2237−.86862)tan(65∘)cos(θ)rD2=(.8686+1.22372e+1.2237−.86862)tan(65∘)cos(θ)
rD1=(2.09232sin(25∘)cos(20∘)−.35512)tan(65∘)cos(20∘)rD2=(2.09232sin(25∘)cos(20∘)+.35512)tan(65∘)cos(20∘))
rD1=(2.09232sin(25∘)cos(20∘)−.35512)tan(65∘)cos(20∘)rD2=(2.09232sin(25∘)cos(20∘)+.35512)tan(65∘)cos(20∘))
rD1=(1.0459(.4497)−.1775)⋅2.1445⋅.9397=.5901 mrD2=(1.0459(.4497)+.1775)⋅2.1445⋅.9397=1.3055m
The height to the first directrix circle is
zD1=rD1cot(θ)=.5901cot(20)=1.6212
and the x and y components are
xD1=rD1 cos(ϕ)=.5901cos(0)=.5901m yD1=rD1cos(ϕ)=.5901sin(0)=0
The height to the second directrix circle is
zD2=rD2cot(θ)=1.3055cot(20)=3.5868 m
and the x and y components are
xD2=rD2cos(ϕ)=1.3055cos(0)=1.3055m yD2=rD2sin(ϕ)=1.3055sin(0)=0
The distance between the two point
√(1.3055−.5901)2+(0−0)2+(3.5868−1.6212)2=√.7152+1.96562=2.09m
This should be equal to 2a
2a=2(a1+a22)=2(.8684+1.22342)=2.09m
This gives the components for a point on the directrix circles as
xD1=rD1 cos(ϕ)=.5901cos(0)=.5901myD1=rD1cos(ϕ)=.5901sin(0)=0zD1=rD1cot(θ)=.5901cot(20)=1.6212 m
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xD2=rD2cos(ϕ)=1.3055cos(0)=1.3055myD2=rD2sin(ϕ)=1.3055sin(0)=0zD2=rD2cot(θ)=1.3055cot(20)=3.5868 m
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xP=2.53cos(ϕ)(cot(θ)+cos(ϕ)cot(65∘)=2.53cos(0)(cot(20∘)+cos(0)cot(65∘)=0.7872yP=2.53sin(ϕ)(cot(θ)+cos(ϕ)cot(65∘)=2.53sin(0)(cot(20∘)+cos(0)cot(65∘)=0zP=2.53cot(θ)(cot(θ)+cos(ϕ)cot(65∘)=2.53cot(20∘)(cot(20∘)+cos(0)cot(65∘)=2.1623
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D2P=√(xD2−xP)2+(yD2−yP)2+(zD2−zP)2=√(1.3055−0.7872)2+(0−0)2+(3.5868−2.1623)2=√(.5183)2+(1.445)2=√.2686+2.0292=1.5158611 m
D1P=√(xP−xD1)2+(yP−yD1)2+(zP−zD1)2=√(0.7872−.5901)2+(0−0)2+(2.1623−1.6212)2=√(.1971)2+(.5411)2=√.0388+.2927=.575879865944 m
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