Respuesta :

y = A cos (B(x - C) + D

A gives the amplitude, which is the maximum displacement, so it's 9.

Answer:

The maximum displacement from the equilibrium position is 9.

Step-by-step explanation:

The given simple harmonic motion is:

[tex]d=9cos(\frac{\pi}{2}t)[/tex]

Differentiating above equation with respect to t, we get

[tex]d'=-9sin(\frac{\pi}{2}t)(\frac{\pi}{2})[/tex]

⇒[tex]d'=-\frac{9{\pi}}{2}sin(\frac{\pi}{2}t)[/tex]

Again differentiating the above equation with respect to t, we have

[tex]d''=-\frac{9({\pi})^{2}}{4}cos(\frac{\pi}{2}t)<0[/tex]

Now, [tex]d'=0[/tex]

⇒[tex]-\frac{9{\pi}}{2}sin(\frac{\pi}{2}t)=0[/tex]

⇒[tex]sin(\frac{\pi}{2}t)=0[/tex]

⇒[tex]\frac{\pi}{2}t=0[/tex]

⇒[tex]t=0[/tex]

Substituting the value of t=0 in d, we get

⇒[tex]d=9cos(\frac{\pi}{2}(0))[/tex]

⇒[tex]d=9cos(0)[/tex]

⇒[tex]d=9(1)[/tex]

⇒[tex]d=9[/tex]

Therefore, the maximum displacement from the equilibrium position is d= 9.