function r =sol1(x1,x2,x3,t)
  r = 2147/100+x2/x1^(1/2)*sinh(x1^(1/2)*t)-(x2*cosh(70*x1^(1/2))-x3)/x1^(1/2)/sinh(70*x1^(1/2))*cosh(x1^(1/2)*t);