Cosine is transformed in the form:
[tex] f(x)=a\cos(b(x-c))+d [/tex]
The amplitude is a
The period of cosine is:
[tex] \frac{2\pi}{b} [/tex]
And the phase shift is always by c, so that means our transformed functon in the form mentioned above looks like:
[tex] f(x)=3\cos{(3(x-\frac{\pi}{6}}))+1 [/tex]
So our period is [tex] \frac{2\pi}{3} [/tex]
Our phase shift is by [tex] \frac{\pi}{6} [/tex] units to the right
and our amplitude is 3.