Problem $2$ Employ the following methods to find the maximum of

f$($x$)=4$ x$-1\mathrm{.}8$ x$^2+1\mathrm{.}2$ x$^3-0\mathrm{.}3$ x$^4$

$($a$)$ Golden$-$section search $($x$\_1=-2,$ x$\_4=4,\backslash$epsi $\_5=1\%).($b$)$ Parabolic interpolation $($x$\_1=1\mathrm{.}75,$ x$^2=2,$ x$^3=2\mathrm{.}5.,$ iterations $.=5).$