Suppose that the piecewise defined function f is defined byf$($x$)=\{3$x$+1,$x$33$x$2+21$x$+28,$x$>3.$

Determine which of the following statements are true.

Select the correct answer below:

f is neither differentiable nor continuous at x$=3.$

f is continuous but not differentiable at x$=3.$

f is both differentiable and continuous at x$=3.$