11-12-2016, 02:19 PM

The command laplace(SIN(t*pi/10)*(Heaviside(t)-Heaviside(t-10)),t,s) works correctly.

[attachment=4139]

Now if instead of the number 10 we use a constant (a), and execute the commands assume(a>0) and laplace(SIN(t*pi/a)*(Heaviside(t)-Heaviside(t-a)),t,s) , the result is not correct.

[attachment=4141]

It should be the same as in the first image, substituting a for 10 in the numerator, and a^2 for 100 in the denominator.

The program XCAS gives correct answers in both cases.

[attachment=4139]

Now if instead of the number 10 we use a constant (a), and execute the commands assume(a>0) and laplace(SIN(t*pi/a)*(Heaviside(t)-Heaviside(t-a)),t,s) , the result is not correct.

[attachment=4141]

It should be the same as in the first image, substituting a for 10 in the numerator, and a^2 for 100 in the denominator.

The program XCAS gives correct answers in both cases.