$7.$ For which of the initial approximations $\backslash ($ x$\_\{1\}=$a$,$ b$,$ c $\backslash )$ and $\backslash ($ d $\backslash ),$ do you think Newton's method will work and lead to the root of the equation $\backslash ($ f$($x$)=0\backslash )?8.$ In the figure, the length of the chord is $4$ cm and the length of the arc is $5$ cm $.$ Find the central angle, in radians, correct to four decimal places. Then give the answer to the nearest degree $($Use NR$-$method$)$