Answer:
B. d = 4 cos(π/3 t)
Explanation:
As at t=0 the amplitude is 4 cm, so the simple harmonic motion will be in cosine form. As in case of sine function, the value of function at t=0 is 0.
sin 0=0
We know that,
y = a. cosb(t + c) + d
Period = 2 π / b
Horizontal shift or phase shift is c,
Amplitude is a,
Vertical shift is d.
As in this case the amplitude is given to be 4, hence = 4
Also the period is given as 6.
That is, 2π/b = 6
b = 2π/6 = π/3
Here horizontal and vertical shifts are 0.
That is c = 0 and d = 0
Plug those values in the above form, we get
y = 4.cos π/3 (t + 0) + 0
y = 4 cos (π/3)t
Answer: B. d = 4 cos(π/3 t)
Hope this will helpful.
Thank you.