$)>({}_2)>({}_2$

For a step input, show that:

a$.y(t)$ can exhibit an extremum $($maximum or minimum value$)$ in the step response only if

$\frac{1-\frac{{}_a}{{}_2}}{1-\frac{{}_a}{f_1}}>1$

$\frac{1-\frac{{}_a}{{}_2}}{1-\frac{{}_a}{{}_1}}>1$

b$.$ Overshoot occurs only for $\frac{T_a}{T_1}>1.$

c$.$ Inverse response occurs only for