function wert=f(t,x)


  wert=144*exp(72*t+6*x)*(2520+1975*cosh(4*x-64*t)+4984*cosh(2*x-8*t)+3415*sinh(64*t-4*x)+9016*sinh(8*t-2*x))...
      /((35*exp(72*t)+72*exp(6*x)+126*exp(64*t+2*x)+180*exp(8*t+4*x))^2);
