Let it's general format be - [tex]f(x) = a \: cos \: b(x - c) + d \\ [/tex] Having frequency as - [tex]f = \frac{b}{2\pi} [/tex] According to provided data -
amplitude : 3 Hence , a = 3
[tex]frequency = \frac{1}{2\pi} [/tex] Hence b = 1
Phase Shift to the left of 2 : c = -2 [ left to the y-axis ]