Questions: Without graphing the function, determine its amplitude or period as requested. y=-3 cos 1/2 x Find the period.
4 pi
pi/2
3 pi/2
-3
Transcript text: Without graphing the function, determine its amplitude or period as requested. $y=-3 \cos \frac{1}{2} x$ Find the period.
$4 \pi$
$\frac{\pi}{2}$
$\frac{3 \pi}{2}$
$-3$
Solution
Solution Steps
To find the period of the cosine function given by \( y = -3 \cos \frac{1}{2} x \), we need to identify the coefficient of \( x \) inside the cosine function. The general form of a cosine function is \( y = a \cos(bx + c) + d \), where the period is given by \( \frac{2\pi}{|b|} \). In this case, \( b = \frac{1}{2} \).
Step 1: Identify the Coefficient
The given function is \( y = -3 \cos \frac{1}{2} x \). In this function, the coefficient of \( x \) is \( b = \frac{1}{2} \).
Step 2: Calculate the Period
The period \( P \) of a cosine function is calculated using the formula:
\[
P = \frac{2\pi}{|b|}
\]
Substituting \( b = \frac{1}{2} \):
\[
P = \frac{2\pi}{\frac{1}{2}} = 2\pi \cdot 2 = 4\pi
\]