Question

A particle moves along the x-axis so that at any time t, measured in seconds, its position is given by s(t)equals = 5cos(t) minus- sin(3t), measured in feet. What is the acceleration of the particle at time t =equals π seconds?

Answer 1

Is the answer 5?

Answer 2

s(t)equals = 5cos(t) minus- sin(3t) ???
why all the words? Just write

s(t) = 5cos(t) - sin(3t)
v(t) = -5sin(t) - 3cos(3t)
a(t) = -5cos(t) + 9sin(3t)

a(π) = -5(-1) + 9(0) = 5

you are correct.