Why is My TI-89 Not Evaluating the Fourier Transform Correctly?

[Samuelcomeau]

TL;DR

My TI-89 is not evaluating the Fourier transform? Change angle to radians and retry.

Summary:: My TI-89 is not evaluating the Fourier transform? Change angle to radians and retry.

Hello, I discovered this forum trying to answer the question: Why is my TI-89 not properly evaluating the Fourier transform? I found no answer, by chance I experimented and found that the calculator must be in radian mode to make proper use of Eulers identity.
So if Integral(x*e^(-i*2*pi*f*t),t) gives the error: Domain Error. Then change your units to radians in the mode menu. Have a nice day.

 

[Tom.G]

Samuel. Good to have you here!

Summary:: My TI-89 is not evaluating the Fourier transform? Change angle to radians and retry.

Integral(x*e^(-i*2*pi*f*t),t) gives the error: Domain Error.

Yeah, that "2*pi" term is a giveaway that it thinks in radians. Keep that in mind for future applications.

Cheers,
Tom