Question

A particle moves along a straight line with equation of motion s = f(t), where s is measured in meters and t in seconds. Find the velocity and speed when t = 3.
f(t) = (t ^-1) - t

Answer 1

simple

f(t) is a function

t is a input, in this case its time

if your getting confused, its the same as f(x) f(y) f(z) f(a) or whatever the letter can be, as long it will explicitly tell you that either x y z or a is a variable (input) of something

so go ahead and put 3 for t in that equation

f(3) = (3 ^ - 1) - 3