Answer
For blue light, we find that the $\theta_{\text {dev }}$ minimum is $139.35^{\circ} \approx 139.4^{\circ}$, and this occurs at $\theta_i$ $=59.52^{\circ}$.
Work Step by Step
For blue light, we find that the $\theta_{\text {dev }}$ minimum is $139.35^{\circ} \approx 139.4^{\circ}$, and this occurs at $\theta_i$ $=59.52^{\circ}$.
