Question

find the amplitude of the following function. y = -2 cos 3x

Explanation:

Step1: Recall the general form of cosine function

The general form of a cosine function is \( y = A\cos(Bx - C) + D \), where the amplitude is given by \( |A| \).

Step2: Identify the value of \( A \) in the given function

In the function \( y = -2\cos(3x) \), we can see that \( A = -2 \).

Step3: Calculate the amplitude

To find the amplitude, we take the absolute value of \( A \). So, the amplitude is \( | -2 | = 2 \).

Answer:

2