Hi Hope,

I think you know that $\cos 0 = 1$ so one solution to $\cos \large \frac{\theta}{30} = 1$ is $\large \frac{\theta}{30} = 0. $ But if $\large \frac{\theta}{30} = 0$ then $\theta = 0$ and hence one solution is $\theta = 0.$

This is not the only solution however since $\cos(360^o)$ is also $1$ so $\large \frac{\theta}{30} = 360^o$ gives $\cos \large \frac{\theta}{30} = 1.$ What is the value of $\theta?$ Are there other solutions?

Penny