Why Does the Calculator Show an Error When Solving for the Angle of Incidence?

[mustang1988]

b]1. A light beam coming from an underwater spotlight exits the water at an angle of 68° to the vertical. At what angle of incidence did it hit the air-water interface from below the surface?


2. snell's law n1sin$$\Theta$$1=n2sin$$\Theta$$2



3. sin$$\Theta$$1=1.33(sin68)
After doing this I took the inverse sin of it and it comes up as error on my calculator. I know it should be an easy question but I don't know where I am messing up.

 

[jgens]

It looks like you've got the equation set up wrong. It should read:

$$n_1\sin{(\theta_1)} = n_2\sin{(\theta_2)}$$

Where $n_1 = 1.33$, $n_2 = 1$, and $\theta_2 = 68$.

 

[mustang1988]

I knew it would be something dumb, thanks for your help.