The general cosine equation is:
[tex]y=a\cdot cos\lbrack b(x-h)\rbrack+k_{}[/tex]
where,
[tex]\begin{gathered} amplitude=|a| \\ period=\frac{2\pi}{b} \\ phase-shift=h \\ y=k\text{ is the midline} \end{gathered}[/tex]
In this case,
[tex]y=3\cdot\cos \lbrack\frac{1}{2}(x-\pi)\rbrack+5[/tex]
where:
[tex]\begin{gathered} a=3 \\ b=\frac{1}{2} \\ h=\pi \\ k=5 \end{gathered}[/tex]
Then,
[tex]\begin{gathered} |3|=3\text{ is the amplitude} \\ \frac{2\pi}{\frac{1}{2}}=2\pi\cdot2=4\pi\text{ is the period } \\ \pi\text{ is the phase shift} \\ y=5\text{ is the midline} \end{gathered}[/tex]
