$*15\mathrm{.}43$ Consider a bistable circuit having a noninverting transfer characteristic with L$+=$L $=5$ V$,$ VTl $=-$l V$,$ and VTH $=+1$ V$.($a$)$ For a $0\mathrm{.}5-$V$-$amplitudc sine$-$wave input having zero average, what is the output? $($b$)$ Describe the output if a sinusoid of frequency f and amplitude of $1\mathrm{.}1$ V is applied at the input. By how much can the average of this sinusoidal input shift before the output becomes a constant value?