what is the amplitude of the cosine curve?

Explanation:

Step1: Identify max and min values

The maximum value of the cosine - curve is approximately 6.5 and the minimum value is approximately 1.5.

Step2: Use amplitude formula

The formula for the amplitude $A$ of a periodic function is $A=\frac{\text{Max}-\text{Min}}{2}$. So, $A = \frac{6.5 - 1.5}{2}$.

Step3: Calculate amplitude

$A=\frac{5}{2}=2.5$.

Answer:

2.5