clc 
// Given that
t = 50 // relaxation time in sec
r = 1 / exp(1) // falls in amplitude and energy
// Sample Problem 13 on page no. 7.26
printf("\n # PROBLEM 13 # \n")
s = 1 / (2 * t)
T = 1 / s // by using formula A=A_exp(-st) and using r=A/A_
printf("\n Standard formula used \n s = 1 / (2 * t). \n T = 1 / s . \n ")
printf("\n Time = %f sec",T)