why the output derivative signal is not perfect ?

Hello i want to derive my sinusoida signal but the result is not that i am searching for.how to solve this problem in simulink ?

[John D'Errico]

There is no reason to answer your own question and then accept the answer just because you want to add some information. I've moved the figure you posted to this comment.

[John D'Errico]

As far as to why it is not perfect, only you know that, because you have not shown hw you generated that signal. We cannot read your mind, or see inside your computer. So post the code that generated this figure.

POST IT IN OR ATTACHED TO A COMMENT.

[El Mehdi FADEL]

[El Mehdi FADEL]

this is my model

[John D'Errico]

I do not have simulink anyway, so I can only point out that you have only posted a picture of the model, instead of the model file itself. So we still cannot see exactly what was done there.

For example, I would want to point out that simulink simulates a system in discrete steps. So that sine wave is not a continuous function. Therefore, a derivative of that sampled function will not be only approximate.

Again, I've never used Simulink, so this might be only a wild guess. But the answer seems pretty clear.