to increase the resistance of strip conductors due to eddy currents at power frequencies is given by lamda=alfa*t/2 (sinh alfa*t + cosh alfa

If your formula is correct then λ is

$${\frac{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{1}}}{{\mathtt{2}}}}\right){\mathtt{\,\times\,}}\left(\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sinh}}{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{180}}}{{\mathtt{\pi}}}}\right)}{\mathtt{\,\small\textbf+\,}}\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cosh}}{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{180}}}{{\mathtt{\pi}}}}\right)}\right)}{\left(\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sin}}{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{180}}}{{\mathtt{\pi}}}}\right)}{\mathtt{\,-\,}}\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{180}}}{{\mathtt{\pi}}}}\right)}\right)}} = {\mathtt{3.872\: \!413\: \!402\: \!889\: \!445\: \!2}}$$

To get -0.56 you must have used 1.08*1 radians inside the trigonometric functions, but with those functions set to degree mode.  You need to (i) set the trig functions to radian mode, or (ii) convert radians to degrees in the trig functions (as I've done above).

Are you sure your formula is correct?  According to http://home.freeuk.net/dunckx/wireless/terman/terman.html it should be 

$$\lambda=\frac{\alpha t}{2}\frac{\sinh{\alpha t}+\sin{\alpha t}}{\cosh{\alpha t}-\cos{\alpha t}}$$

so that λ is:

$${\frac{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{1}}}{{\mathtt{2}}}}\right){\mathtt{\,\times\,}}\left(\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sinh}}{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{180}}}{{\mathtt{\pi}}}}\right)}{\mathtt{\,\small\textbf+\,}}\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sin}}{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{180}}}{{\mathtt{\pi}}}}\right)}\right)}{\left(\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cosh}}{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{180}}}{{\mathtt{\pi}}}}\right)}{\mathtt{\,-\,}}\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\frac{{\mathtt{1.08}}{\mathtt{\,\times\,}}{\mathtt{180}}}{{\mathtt{\pi}}}}\right)}\right)}} = {\mathtt{1.007\: \!533\: \!873\: \!661\: \!752\: \!1}}$$

If your formula is correct, simply use the calculator on this site (you could select radian mode first, and then wouldn't need to invoke the 180/pi factor).

i got the answer as -0.56,it should be like this alfa*t/2{and rest of the thing}