the function (f(x)=acos bx + c) is plotted on the graph shown below.\nwhat are the values of (a), (b), and…

the function (f(x)=acos bx + c) is plotted on the graph shown below.\nwhat are the values of (a), (b), and (c)?\na (a = 2, b = 6, c = 3)\nb (a = 2, b = 3, c = 1)\nc (a = 4, b = 6, c = 5)\nd (a = 4, b=\frac{pi}{3}, c = 3)
Answer
Explanation:
Step1: Find the vertical shift (c)
The mid - line of the cosine function is given by $y = c$. The maximum value of the function is $y = 5$ and the minimum is $y = 1$. The mid - line $c=\frac{5 + 1}{2}=3$.
Step2: Find the amplitude (a)
The amplitude $a$ of a cosine function $y=a\cos(bx)+c$ is given by $a=\frac{\text{Max}-\text{Min}}{2}$. Here, $\text{Max}=5$, $\text{Min}=1$, so $a=\frac{5 - 1}{2}=2$.
Step3: Find the value of b
The period $T$ of the cosine function is the distance between two consecutive maxima or minima. From the graph, the period $T=\frac{\pi}{3}-\frac{\pi}{6}=\frac{\pi}{6}$. The formula for the period of $y = a\cos(bx)+c$ is $T=\frac{2\pi}{|b|}$. Since $T=\frac{\pi}{3}$, we have $\frac{2\pi}{b}=\frac{\pi}{3}$, solving for $b$ gives $b = 6$.
Answer:
A. $a = 2, b = 6, c = 3$