How to input this function for calculating furrier series

Hello everyone

I have a very simple code for Adcanced mathematics and I cant find the way to input the Function.

this code is to find furrier series and plot it then compare it with the main function plot.

so this is my code

and my problem is that i cant find a way to input this function and yes I have search the net for days now and cant find anything useful

Please guide me and Thank you

Answer 1

[Walter Roberson]

y = piecewise(x < 2, 2*x-8, x > 2, x*cos(x), nan)

The nan is there to emphasize to readers that the output of piecewise() returns nan when none of the input conditions match, as would be the case for x == 2 exactly.

Reminder: boundary conditions are important for fourier transform purposes.

[Kamyar D]

Thank you very very much