DERIVE for Windows version 5.00 DfW file saved on 05 Jan 2001  Segmento(, r, t):=[-1 + y^2 + x^2 = 0, - r^2 + y^2 + (x - )^2 = 0, [ + r(1 - t^2)/(1 + t^2), r2t/(1 + t^2); - r(1 - t^4 + r^2(t^4 - 1) - 2r(t^4 + 1) + ^2(t^4 - 1) + 2t(t^2 + 1)((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))(-1 - 2t^2 - t^4 + r^2(1 - 2t^2 + t^4) + 2r(1 - t^4) + ^2(1 + 2t^2 + t^4))/((t^2 + 1)(- r^2(t^2 + 1)(-1 + 6t^2 - t^4 + r^2(1 - 2t^2 + t^4)) + 2r(t^2 - 1)(-1 - 2t^2 - t^4 + 2r^2(t^4 + 1)) - ^2(t^2 + 1)(-1 - 2t^2 - t^4 + 2r^2(3 - 4t^2 + 3t^4)) + 4^3r(t^2 + 1)(t^4 - 1) - ^4(t^2 + 1)^3 + 4rt(t^2 + 1)((t^2 + 1) + r(1 - t^2))((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))), - (x((t^2 + 1)^(3/2)((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)) - 2rt((t^2 + 1) + r(1 - t^2))) + r((t^2 - 1)(t^2 + 1)((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)) - 2t(-1 - t^2 + r(1 - t^2) + ^2(t^2 + 1))))/(-1 - 2t^2 - t^4 + r^2(1 - 2t^2 + t^4) + 2r(1 - t^4) + ^2(1 + 2t^2 + t^4))]] m(, r, t):=(2rt((t^2 + 1) + r(1 - t^2)) - (t^2 + 1)^(3/2)(^2(t^2 + 1) + 2r(1 - t^2) + (r^2 - 1)(t^2 + 1)))/(^2(t^4 + 2t^2 + 1) + 2r(1 - t^4) + r^2(t^4 - 2t^2 + 1) - t^4 - 2t^2 + -1) s(, r, t):=2(2rt(t^2 + 1)(^2(t^2 + 1) + 2r(1 - t^2) + (r^2 - 1)(t^2 + 1))(^2(t^2 + 1)^2 + 2r(t^2 + 1)(1 - t^2) + r^2(t^2 - 1)^2 + t^4 + 2t^2 + 1) - ^5(t^4 + 2t^2 + 1)^2 + 4^4r(t^4 - 1)(t^4 + 2t^2 + 1) - ^3(t^4 + 2t^2 + 1)(6r^2(t^4 - 2t^2 + 1) - t^4 - 2t^2 + -1) + ^2r(t^2 + 1)(t^2 - 1)(4r^2(t^2 - 1)^2 - t^4 - 2t^2 + -1) - r^2(r^2(t^4 - 2t^2 + 1)^2 + t^8 + 8t^6 + 14t^4 + 8t^2 + 1) + r(t^2 + 1)(t^2 - 1)(r^2(t^4 + 6t^2 + 1) - (t^2 + 1)^2))/((t^2 + 1)(4rt(t^2 + 1)((t^2 + 1) + r(1 - t^2))(^2(t^2 + 1) + 2r(1 - t^2) + (r^2 - 1)(t^2 + 1)) - ^4(t^2 + 1)^3 + 4^3r(t^2 + 1)(t^4 - 1) - ^2(t^2 + 1)(2r^2(3t^4 - 4t^2 + 3) - t^4 - 2t^2 + -1) + 2r(t^2 - 1)(2r^2(t^4 + 1) - t^4 - 2t^2 + -1) + - r^2(t^2 + 1)(r^2(t^4 - 2t^2 + 1) - t^4 + 6t^2 + -1))) - + r(1 - 2/(t^2 + 1)) segmento(, r, t):=[-1 + y^2 + x^2 = 0, - r^2 + y^2 + (x - )^2 = 0, [ + r(1 - t^2)/(1 + t^2), r2t/(1 + t^2)], [- r(1 - t^4 + r^2(t^4 - 1) - 2r(t^4 + 1) + ^2(t^4 - 1) + 2t(t^2 + 1)((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))(-1 - 2t^2 - t^4 + r^2(1 - 2t^2 + t^4) + 2r(1 - t^4) + ^2(1 + 2t^2 + t^4))/((t^2 + 1)(- r^2(t^2 + 1)(-1 + 6t^2 - t^4 + r^2(1 - 2t^2 + t^4)) + 2r(t^2 - 1)(-1 - 2t^2 - t^4 + 2r^2(t^4 + 1)) - ^2(t^2 + 1)(-1 - 2t^2 - t^4 + 2r^2(3 - 4t^2 + 3t^4)) + 4^3r(t^2 + 1)(t^4 - 1) - ^4(t^2 + 1)^3 + 4rt(t^2 + 1)((t^2 + 1) + r(1 - t^2))((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))), r(2t(t^2 + 1)((t^2 + 1)^2(1 + 2t^2 + t^4) - 4r^2(t^2 + 1)^2(1 - 2t^2 + t^4) + 2r^4(1 - 2t^2 + t^4)(1 + 4t^2 + t^4) + r^6(t^2 - 1)^2(1 - 2t^2 + t^4)) + 2rt(1 - t^2)(- 7(t^2 + 1)^2(1 + 2t^2 + t^4) + 3r^2(t^2 + 1)^2(3 - 2t^2 + 3t^4) + 4r^4(1 - t^2 - t^6 + t^8)) + 2^2t(t^2 + 1)(- 3(t^2 + 1)^4 + 15r^2(t^2 + 1)^2(1 - 2t^2 + t^4) + r^4(5 - 8t^2 + 6t^4 - 8t^6 + 5t^8)) + 2^3rt(1 - t^2)(1 + 2t^2 + t^4)(4r^2t^2 + 11(t^2 + 1)^2) + 2^4t(t^2 + 1)^3(3(t^2 + 1)^2 - 5r^2(1 - 2t^2 + t^4)) + 8^5rt(t^2 - 1)(t^2 + 1)^4 - 2^6t(t^2 + 1)^5 + (t^2 - 1)(t^2 + 1)((t^2 + 1)^2(1 + 2t^2 + t^4) - r^2(t^2 + 1)^2(3 - 10t^2 + 3t^4) + 2r^4(1 - 2t^2 + t^4)(1 + 4t^2 + t^4) + 2r(1 - t^4)(4r^2(1 + t^2 + t^4) - 3(t^2 + 1)^2) + 3^2(1 + 2t^2 + t^4)(4r^2(1 - t^2 + t^4) - (t^2 + 1)^2) - 8^3r(t^2 + 1)(-1 - t^2 + t^4 + t^6) + 2^4(t^2 + 1)(1 + 3t^2 + 3t^4 + t^6))((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))/((t^2 + 1)(- r^2(t^2 + 1)(-1 + 6t^2 - t^4 + r^2(1 - 2t^2 + t^4)) + 2r(t^2 - 1)(-1 - 2t^2 - t^4 + 2r^2(t^4 + 1)) - ^2(t^2 + 1)(-1 - 2t^2 - t^4 + 2r^2(3 - 4t^2 + 3t^4)) + 4^3r(t^2 + 1)(t^4 - 1) - ^4(t^2 + 1)^3 + 4rt(t^2 + 1)((t^2 + 1) + r(1 - t^2))((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))(-1 - t^2 + r(1 - t^2) + (t^2 + 1))(1 + t^2 + r(1 - t^2) + (t^2 + 1)))], [- r(1 - t^4 + r^2(t^4 - 1) - 2r(t^4 + 1) + ^2(t^4 - 1) + 2t(t^2 + 1)((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))(-1 - 2t^2 - t^4 + r^2(1 - 2t^2 + t^4) + 2r(1 - t^4) + ^2(1 + 2t^2 + t^4))/((t^2 + 1)(- r^2(t^2 + 1)(-1 + 6t^2 - t^4 + r^2(1 - 2t^2 + t^4)) + 2r(t^2 - 1)(-1 - 2t^2 - t^4 + 2r^2(t^4 + 1)) - ^2(t^2 + 1)(-1 - 2t^2 - t^4 + 2r^2(3 - 4t^2 + 3t^4)) + 4^3r(t^2 + 1)(t^4 - 1) - ^4(t^2 + 1)^3 + 4rt(t^2 + 1)((t^2 + 1) + r(1 - t^2))((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))), r(2t(t^2 + 1)((t^2 + 1)^2(1 + 2t^2 + t^4) - 4r^2(t^2 + 1)^2(1 - 2t^2 + t^4) + 2r^4(1 - 2t^2 + t^4)(1 + 4t^2 + t^4) + r^6(t^2 - 1)^2(1 - 2t^2 + t^4)) + 2rt(1 - t^2)(- 7(t^2 + 1)^2(1 + 2t^2 + t^4) + 3r^2(t^2 + 1)^2(3 - 2t^2 + 3t^4) + 4r^4(1 - t^2 - t^6 + t^8)) + 2^2t(t^2 + 1)(- 3(t^2 + 1)^4 + 15r^2(t^2 + 1)^2(1 - 2t^2 + t^4) + r^4(5 - 8t^2 + 6t^4 - 8t^6 + 5t^8)) + 2^3rt(1 - t^2)(1 + 2t^2 + t^4)(4r^2t^2 + 11(t^2 + 1)^2) + 2^4t(t^2 + 1)^3(3(t^2 + 1)^2 - 5r^2(1 - 2t^2 + t^4)) + 8^5rt(t^2 - 1)(t^2 + 1)^4 - 2^6t(t^2 + 1)^5 + (t^2 - 1)(t^2 + 1)((t^2 + 1)^2(1 + 2t^2 + t^4) - r^2(t^2 + 1)^2(3 - 10t^2 + 3t^4) + 2r^4(1 - 2t^2 + t^4)(1 + 4t^2 + t^4) + 2r(1 - t^4)(4r^2(1 + t^2 + t^4) - 3(t^2 + 1)^2) + 3^2(1 + 2t^2 + t^4)(4r^2(1 - t^2 + t^4) - (t^2 + 1)^2) - 8^3r(t^2 + 1)(-1 - t^2 + t^4 + t^6) + 2^4(t^2 + 1)(1 + 3t^2 + 3t^4 + t^6))((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))/((t^2 + 1)(- r^2(t^2 + 1)(-1 + 6t^2 - t^4 + r^2(1 - 2t^2 + t^4)) + 2r(t^2 - 1)(-1 - 2t^2 - t^4 + 2r^2(t^4 + 1)) - ^2(t^2 + 1)(-1 - 2t^2 - t^4 + 2r^2(3 - 4t^2 + 3t^4)) + 4^3r(t^2 + 1)(t^4 - 1) - ^4(t^2 + 1)^3 + 4rt(t^2 + 1)((t^2 + 1) + r(1 - t^2))((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))(-1 - t^2 + r(1 - t^2) + (t^2 + 1))(1 + t^2 + r(1 - t^2) + (t^2 + 1))); + r(1 - t^2)/(1 + t^2), r2t/(1 + t^2)]] segmentotangente(, r, t):=[x^2 + y^2 + -1 = 0, (x - )^2 + y^2 + - r^2 = 0, [ + r(1 - t^2)/(1 + t^2), r2t/(1 + t^2); s(, r, t), u(, r, t)]] tangente(, r, t):=[-1 + y^2 + x^2 = 0, - r^2 + y^2 + (x - )^2 = 0, [ + r(1 - t^2)/(1 + t^2), r2t/(1 + t^2)], y = r2t/(1 + t^2) + (2rt((t^2 + 1) + r(1 - t^2)) - (t^2 + 1)^(3/2)((r^2 - 1)(t^2 + 1) + 2r(1 - t^2) + ^2(t^2 + 1)))/(-1 - 2t^2 - t^4 + r^2(1 - 2t^2 + t^4) + 2r(1 - t^4) + ^2(1 + 2t^2 + t^4))(x - ( + r(1 - t^2)/(1 + t^2)))] u(, r, t):=r2t/(1 + t^2) + m(, r, t)(s(, r, t) - ( + r(1 - t^2)/(1 + t^2))) hCross:=APPROX(- 6659090909090909/500000000000000) vCross:=APPROX(45238095238095237/10000000000000000) := (CTextObj C{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Un ensayo para hacer los c\'e1lculos de Poncelet. \par \par Tomamos la circunferencia de radio 1 y centro (0,0) como circunferencia interior y la de radio r y centro (\'a9,0) como la circunferencia exterior (r habr\'e1 de ser mayor que 1+\'a9 para que la circunferencia unitaria sea interior). \par Un punto gen\'e9rico de la exterior ser\'e1 \par } CExpnObj8User'[alpha+r*(1-t^2)/(1+t^2),r*2*t/(1+t^2)]={\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Trazamos una tangente a la circunferencia interior. Primero una recta de pendiente m \par } 8xJUser.y=r*2*t/(1+t^2)+m(x-(alpha+r*(1-t^2)/(1+t^2)))Vh&{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Hallamos m para que sea tangente a la circunferencia interior \par } 8tUser x^2+y^2=18User8x^2+(r*2*t/(1+t^2)+m(x-(alpha+r*(1-t^2)/(1+t^2))))^2-1=0 {\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Esta es la ecuaci\'f3n que resulta \par } 8^Userx^2*m(+1)^2*(t^2+1)^2+2*m(x)*(t^2+1)*(r*(m(t^2-1)+2*t)-alpha*m(t^2+1))+alpha^2*(m(t^2+1)^2)^2-2*alpha*m(r)*(t^2+1)*(m(t^2-1)+2*t)+(m(r)^2)^2*(t^2-1)^2+4*m(r)^2*t*(t^2-1)+4*r^2*t^2-(t^2+1)^2=0j{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Obtenemos su discriminante, que anulamos y as\'ed, resolviendo la ecuaci\'f3n en m que resulta, obtenemos los dos valores de m que hacen tangentes las rectas desde el punto correspondiente al par\'e1metro t \par } 8 User(2*m(t^2+1)*(r*(m(t^2-1)+2*t)-alpha*m(t^2+1)))^2-4*((m(+1)^2*(t^2+1)^2)*(alpha^2*(m(t^2+1)^2)^2-2*alpha*m(r)*(t^2+1)*(m(t^2-1)+2*t)+(m(r)^2)^2*(t^2-1)^2+4*m(r)^2*t*(t^2-1)+4*r^2*t^2-(t^2+1)^2))=0*"{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Elegimos la primera pendiente, por ejemplo, y comprobamos \par } 6H7{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 La recta tangente desde el punto correspondiente al par\'e1metro t es entonces \par } 8T Sub(#2)y=r*2*t/(1+t^2)+(2*r*t*(alpha*(t^2+1)+r*(1-t^2))-(t^2+1)^(3/2)*SQRT(alpha^2*(t^2+1)+2*alpha*r*(1-t^2)+(r^2-1)*(t^2+1)))/(alpha^2*(t^4+2*t^2+1)+2*alpha*r*(1-t^4)+r^2*(t^4-2*t^2+1)-t^4-2*t^2-1)*(x-(alpha+r*(1-t^2)/(1+t^2))),>{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Comprobamos \par } 8J^User>tangente(alpha,r,t):=[x^2+y^2-1=0,(x-alpha)^2+y^2-r^2=0,[alpha+r*(1-t^2)/(1+t^2),r*2*t/(1+t^2)],y=r*2*t/(1+t^2)+(2*r*t*(alpha*(t^2+1)+r*(1-t^2))-(t^2+1)^(3/2)*SQRT(alpha^2*(t^2+1)+2*alpha*r*(1-t^2)+(r^2-1)*(t^2+1)))/(alpha^2*(t^4+2*t^2+1)+2*alpha*r*(1-t^4)+r^2*(t^4-2*t^2+1)-t^4-2*t^2-1)*(x-(alpha+r*(1-t^2)/(1+t^2)))]8jvUser tangente(2,5,1)` Approx(#9){Gzt? =[x^2+y^2-1=0,x^2-4*x+y^2-21=0,[2,5],y=0.0016469*(953*x+1130)]8User tangente(3,7,2)8 Approx(#11)~jt? E[x^2+y^2-1=0,x^2-6*x+y^2-40=0,[-1.2,5.6],y=-0.00355871*(7893*x+7898)]<{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Se ve que va bien por ahora. \par \par Tratamos a continuaci\'f3n de obtener la otra intersecci\'f3n de esta recta con la circunferencia exterior. Como conocemos una intersecci\'f3n, la otra se obtiene f\'e1cilmente. Substituimos en la ecuaci\'f3n de la circunferencia \par } 8H`User (x-alpha)^2+y^2-r^2=0l~{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 la y por la de la recta \par } 8VUsery=r*2*t/(1+t^2)+(2*r*t*(alpha*(t^2+1)+r*(1-t^2))-(t^2+1)^(3/2)*SQRT(alpha^2*(t^2+1)+2*alpha*r*(1-t^2)+(r^2-1)*(t^2+1)))/(alpha^2*(t^4+2*t^2+1)+2*alpha*r*(1-t^4)+r^2*(t^4-2*t^2+1)-t^4-2*t^2-1)*(x-(alpha+r*(1-t^2)/(1+t^2)))bt{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Resulta la ecuaci\'f3n en x \par } 8H UserBx^2*(t^2+1)*(4*r*t*SQRT(t^2+1)*(alpha*(t^2+1)+r*(1-t^2))*SQRT(alpha^2*(t^2+1)+2*alpha*r*(1-t^2)+(r^2-1)*(t^2+1))-alpha^4*(t^2+1)^3+4*alpha^3*r*(t^2+1)*(t^4-1)-alpha^2*(t^2+1)*(2*r^2*(3*t^4-4*t^2+3)-t^4-2*t^2-1)+2*alpha*r*(t^2-1)*(2*r^2*(t^4+1)-t^4-2*t^2-1)-r^2*(t^2+1)*(r^2*(t^4-2*t^2+1)-t^4+6*t^2-1))-2*x*(2*r*t*SQRT(t^2+1)*SQRT(alpha^2*(t^2+1)+2*alpha*r*(1-t^2)+(r^2-1)*(t^2+1))*(alpha^2*(t^2+1)^2+2*alpha*r*(t^2+1)*(1-t^2)+r^2*(t^2-1)^2+t^4+2*t^2+1)-alpha^5*(t^4+2*t^2+1)^2+4*alpha^4*r*(t^4-1)*(t^4+2*t^2+1)-alpha^3*(t^4+2*t^2+1)*(6*r^2*(t^4-2*t^2+1)-t^4-2*t^2-1)+alpha^2*r*(t^2+1)*(t^2-1)*(4*r^2*(t^2-1)^2-t^4-2*t^2-1)-alpha*r^2*(r^2*(t^4-2*t^2+1)^2+t^8+8*t^6+14*t^4+8*t^2+1)+r*(t^2+1)*(t^2-1)*(r^2*(t^4+6*t^2+1)-(t^2+1)^2))+(4*r*t*(t^2+1)^(3/2)*SQRT(alpha^2*(t^2+1)+2*alpha*r*(1-t^2)+(r^2-1)*(t^2+1))-alpha^5*(t^2+1)^3+3*alpha^4*r*(t^6+t^4-t^2-1)+alpha^3*(t^2+1)*((t^2+1)^2-2*r^2*(t^4-4*t^2+1))+alpha^2*r*(1-t^2)*(2*r^2*(t^4+4*t^2+1)-(t^2+1)^2)+alpha*r^2*(t^2+1)*(3*r^2*(t^4-2*t^2+1)-5*t^4-2*t^2-5)+r*(1-t^2)*(r^4*(t^4-2*t^2+1)-3*r^2*(t^2+1)^2+2*(t^2+1)^2))*(alpha*(t^2+1)+r*(1-t^2))=0T f {\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Una de sus soluciones es la que conocemos \par } 8r Userx=alpha+r*(1-t^2)/(1+t^2)  {\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Comprobamos \par }    Simp(User)?0=0  0{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 La otra soluci\'f3n s para x la obtenemos de la suma x+s=-b/a, es decir \par }   {\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Ahora hallamos la y correspondiente a esta s \par } 8, xh User.y=r*2*t/(1+t^2)+m(x-(alpha+r*(1-t^2)/(1+t^2)))8t ` Users(alpha,r,t):=2*(2*r*t*SQRT(t^2+1)*SQRT(alpha^2*(t^2+1)+2*alpha*r*(1-t^2)+(r^2-1)*(t^2+1))*(alpha^2*(t^2+1)^2+2*alpha*r*(t^2+1)*(1-t^2)+r^2*(t^2-1)^2+t^4+2*t^2+1)-alpha^5*(t^4+2*t^2+1)^2+4*alpha^4*r*(t^4-1)*(t^4+2*t^2+1)-alpha^3*(t^4+2*t^2+1)*(6*r^2*(t^4-2*t^2+1)-t^4-2*t^2-1)+alpha^2*r*(t^2+1)*(t^2-1)*(4*r^2*(t^2-1)^2-t^4-2*t^2-1)-alpha*r^2*(r^2*(t^4-2*t^2+1)^2+t^8+8*t^6+14*t^4+8*t^2+1)+r*(t^2+1)*(t^2-1)*(r^2*(t^4+6*t^2+1)-(t^2+1)^2))/((t^2+1)*(4*r*t*SQRT(t^2+1)*(alpha*(t^2+1)+r*(1-t^2))*SQRT(alpha^2*(t^2+1)+2*alpha*r*(1-t^2)+(r^2-1)*(t^2+1))-alpha^4*(t^2+1)^3+4*alpha^3*r*(t^2+1)*(t^4-1)-alpha^2*(t^2+1)*(2*r^2*(3*t^4-4*t^2+3)-t^4-2*t^2-1)+2*alpha*r*(t^2-1)*(2*r^2*(t^4+1)-t^4-2*t^2-1)-r^2*(t^2+1)*(r^2*(t^4-2*t^2+1)-t^4+6*t^2-1)))-alpha+r*(1-2/(t^2+1))8l 8 Userm(alpha,r,t):=(2*r*t*(alpha*(t^2+1)+r*(1-t^2))-(t^2+1)^(3/2)*SQRT(alpha^2*(t^2+1)+2*alpha*r*(1-t^2)+(r^2-1)*(t^2+1)))/(alpha^2*(t^4+2*t^2+1)+2*alpha*r*(1-t^4)+r^2*(t^4-2*t^2+1)-t^4-2*t^2-1)8D ` UserQu(alpha,r,t):=r*2*t/(1+t^2)+m(alpha,r,t)*(s(alpha,r,t)-(alpha+r*(1-t^2)/(1+t^2)))8 @Usersegmentotangente(alpha,r,t):=[x^2+y^2-1=0,(x-alpha)^2+y^2-r^2=0,[[alpha+r*(1-t^2)/(1+t^2),r*2*t/(1+t^2)],[s(alpha,r,t),u(alpha,r,t)]]]8LXUsersegmentotangente(2,5,3)8dpUsersegmentotangente(3,5,7)|{\rtf1\ansi\deff0\deftab720{\fonttbl{\f0\fswiss MS Sans Serif;}{\f1\froman\fcharset2 Symbol;}{\f2\fswiss\fprq2 System;}{\f3\fmodern\fcharset2 DfW5 Printer;}} {\colortbl\red0\green0\blue0;} \deflang1034\pard\plain\f3\fs24 Por los experimentos va bien. Lo que ahora hace falta es trazar la tangente desde el punto que hemos obtenido y luego la otra y expresar que se cierra el tri\'e1ngulo. De esas condiciones eliminar la t. Un buen l\'edo. \par }