Acontinuous signal is described by 15 sin( 100t + pi/2).
its numerical value at t = 0 seconds is given by

a. 15.
b. pi/2.
c. 100.
d. 0.

Option A) 15        

Step-by-step explanation:

We are given the following in the question:

The above expression describes a continuous signal.

We have to find the numerical value at t = 0.

Putting t = 0, we get,

Thus, the value of the signal is 15 at t = 0.

Option A) 15

in simplified version   it would be x ≤-4

step-by-step explanation:

multiply each term in x ≤-4 by -1