Question

a particle moves along the x-axis so that anytime t comma measured in seconds it's position is given by...​

Answer 1

Given the position function s(t), you can get the acceleration function by differentiating s twice:

velocity = s'(t) = -5 sin(t ) + 3 cos(3t )

acceleration = s''(t) = -5 cos(t ) - 9 sin(3t )

Then when t = π, the particle's acceleration is

s''(π) = -5 cos(π) - 9 sin(3π)

… = -5 • (-1) - 9 • 0 = 5