Why is $y(t)=x(t/2)$ a non-causal system?

1. What makes a system non-causal?
2. How do you check if a system is causal or not?
3. What is non-causal?
4. Which of the following is an example for non-causal system?

What makes a system non-causal?

A system whose output or response at any time instant (t) depends upon future values of the input is called the non-causal system. The non-causal systems can generate an output before the input is given, hence they are also known as anticipative systems.

How do you check if a system is causal or not?

A system is said to be causal if it does not respond before the input is applied. In other words, in a causal system, the output at any time depends only on the values of the input signal up to and including that time and does not depend on the future values of the input.

What is non-causal?

non·​caus·​al ˌnän-ˈkȯ-zəl. : not causal: such as. : not being a cause of something. causal versus noncausal actions. : not of, relating to, or involving causation : not marked by cause and effect.

Which of the following is an example for non-causal system?

Which of the following is an example for non- causal system? Explanation: y[n] = ¹⁄₃ x[n-1] + x[n] + x[n+1] is an example for non- causal system since the output y [n] depends on the future value of the input namely x [n+1].