R=36 u; r=16 u;
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HE=1152/r; AD=768/r;
(R+r)²-(R-r)²=(768/r)²;
4Rr=768²/r²;
R=147456/r³; (1)
HO₁²=(2R-r)²+(768/r)²;
HO₁²=(1152/r)²+r²;
uguagliando i due valori si ha:
4R²-4Rr+r²+768²/r²=1152²/r²+r²;
4R(R-r)=737280/r²;
R(R-r)=184320/r²;
(147456/r)(147456-r⁴)/r³=184320;
4(147456-r⁴)=5r⁴;
9r⁴=147456•4;
r⁴=65536=16⁴;
r=16 u;
R=147456/16³=36 u;