Answer:
C
Step-by-step explanation:
Given a sine/cos function in the form [tex]f(x)=A cos (Bx+C)[/tex], we can say that:
A is the Amplitude
[tex]\frac{2\pi}{B}[/tex] is the period
[tex]-\frac{C}{B}[/tex] is the phase shift
From the function given [tex]\frac{2}{3}cos(4t+3\pi)[/tex], we can say
A = [tex]\frac{2}{3}[/tex]
B = 4
C = 3π
Now we can figure out:
Amplitude = 2/3
Period = 2π/4 = π/2
Phase Shift = -3π/4
The correct answer choice is C
