The equation which models the distance (d) of the weight from its equilibrium after time (t) is equal to d = -9cos(2π/3)t.
<h3>What is the period of a cosine function?</h3>
The period of a cosine function simply means the total length (distance) of the interval of values on the x-axis over which a graph lies and it's repeated.
Since the weight attached is at its lowest point at time (t = 0), therefore, the amplitude of equation will be negative nine (-9)
For the angular velocity at time period (t = 3s), we have:
ω = 2π/T
ω = 2π/3
Mathematically, the standard equation of a cosine function is given by:
y = Acos(ω)t
Substituting the given parameters into the formula, we have;
d = -9cos(2π/3)t.
Read more on cosine function here: brainly.com/question/4599903
Option a:
is the equivalent expression.
Explanation:
The expression is
where 
Let us simplify the expression, to determine which expression is equivalent from the four options.
Multiplying the powers, we get,

Cancelling the like terms, we have,

This equation can also be written as,

Multiplying the terms in denominator, we have,

Thus, the expression which is equivalent to
is 
Hence, Option a is the correct answer.
Answer:
Just need points well I wish I was that smart
It's about 2.064 if you make the number an improper fraction then divide