Answer:
Amplitude = 3.5
Step-by-step explanation:
The amplitude of a sinusoidal function is one-half of the positive difference between the maximum and minimum values of a function.
Given the cosine function [tex]m(x)=-3.5\cos x[/tex]
The maximum and the minimum values of the function [tex]y=\cos x[/tex] are 1 and -1, so the maximum and the minimum values of the function [tex]m(x)[/tex] are 3.5 and -3.5.
Positive difference:
[tex]3.5-(-3.5)=3.5+3.5=7[/tex]
Half of the difference:
[tex]\dfrac{1}{2}\cdot 7=3.5[/tex]