A beam of unpolarized light travels from a denser medium of...

According to Brewster's law, when light travels from a medium of refractive index $\mu_1$ to a medium of refractive index $\mu_2$, the polarizing angle $i_p$ is given by $\tan(i_p) = \dfrac{\mu_2}{\mu_1}$.

Since the light is traveling from a denser medium to a rarer medium, we have $\mu_1 > \mu_2$.

This implies that the relative refractive index $\dfrac{\mu_2}{\mu_1} < 1$.

Therefore, $\tan(i_p) < 1$.

Since $i_p$ must be a positive angle, and $\tan(45^\circ) = 1$, the polarizing angle must lie in the range $0^\circ < i_p < 45^\circ$.

Answer: $0^\circ < i_p < 45^\circ$