Matlab - soluciones ecuacion no lineal

x0=0;

y0=20;

z0=0;

h=20;

r=2;

R=5;

alfa=0;

beta=70;

u=[sind(alfa) cosd(alfa)*cosd(beta) sind(beta)];%vector de entrada del rayo

u=u/norm(u);

fsolve({x0+lambda*u(1)-(cos(asin((y0+lambda*u(2))/(R+r*cos(asin((z0+lambda*u(3))/r))))))*(R+r*cos(asin((z0+lambda*u(3))/r)))},{X},'complex')%aqui necesito sacar las soluciones de lambda

x=[x0 x0+lambda*u(1)];

y=[y0 y0+lambda*u(2)];

z=[z0 z0+lambda*u(3)];

%plot3(x,y,z)

clear all

x0=0;y0=20; z0=0;

h=20; r=2;R=5;

alfa=0;beta=70;

u=[sind(alfa) cosd(alfa)*cosd(beta) sind(beta)];%vector de entrada del rayo

u=u/norm(u);

syms t

a=x0+t*u(1)-(cos(asin((y0+t*u(2))/(R+r*cos(asin((z0+t*u(3))/r))))))*(R+r*cos(asin((z0+t*u(3))/r)));

t=solve(a,'t');

x=[x0 x0+t(1)*u(1)];

y=[y0 y0+t(1)*u(2)];

z=[z0 z0+t(1)*u(3)];

figure(1)

plot3(x,y,z)

grid

x=[x0 x0+t(2)*u(1)];

y=[y0 y0+t(2)*u(2)];

z=[z0 z0+t(2)*u(3)];

figure(2)

plot3(x,y,z)

grid