Which of the following signals is monotonic?
A. x(t) = t^3 – 2t
B. x(t) = sin(t)
C. x(t) = sin^2(t) + cos^2(t) – 2t
D. x(t) = log(cos(t))
Answer:A
Which of the following signals is monotonic?
A. x(t) = t^3 – 2t B. x(t) = sin(t) C. x(t) = sin^2(t) + cos^2(t) – 2t D. x(t) = log(cos(t))
Explanation: c) reduces to 1 – 2t, which is a strictly decreasing function.