\(n' = \frac{v}{{v - {v_S}}}n\)= \(\frac{{330}}{{330 - 33}} \times 450 = \frac{{330}}{{297}} \times 450 = 500\,Hz\)
$(a)$ $\left(x^2-v t\right)^2$
$(b)$ $\log \left[\frac{(x+v t)}{x_0}\right]$
$(c)$ $e^{\left\{-\frac{(x+v t)}{x_0}\right\}^2}$
$(d)$ $\frac{1}{x+v t}$