Compare the Bessel function model with two approximation: g$($phi$\_$e$)=$g$*$e$^(-2\mathrm{.}6($phi$\_$e$/$phi$\_$b$)^2)$ and g$($phi$\_$e$)=$g$*$e$^(-2\mathrm{.}7($phi$\_$e$/$phi$\_$b$)^2)$ by plotting using Matlab each on the same graph with phi$\_$e$=0\mathrm{.}1.$