QuestionThe cosine graph shown has a range $[-3,9]$. The graph has an equation in the form $y=a \cos [b(x-c)]+d, a>0$. Determine the equation if the graph has a minimum possible phase shift. max $=9$ min $=-5$ $$\begin{array}{l} y=a \cos [b(x-c)]+d \\ a=\frac{\max -\min }{2} \quad d=\frac{m_{a x}+\min }{2} \\ a=\frac{4-(-3)}{2} \quad d=\frac{9+(-3)}{2} \\ a=6 \\ a=3 \end{array}$$ $$y=6 \cos [b(x-c)]+3$$