Very Basic Fourier Transform Equation

[DiamondV]

Homework Statement

So well, in class we were shown this equation for the Fourier transform:
http://puu.sh/nHsWo/042d1d01ba.png
First equation turns a function of time into frequency(notice there's no - in the exponent of e)
Second one does the opposite(notice there is a - in the exponent of e)

I searched online and found this video:

the first equation on the left transforms function of time into frequency but there is a - this time why so?
arent they meant to be the same

Homework Equations

The Attempt at a Solution

 

[BvU]

It's just the sign of f. The video definition is more sensible. Can you guess why I say that ?

 

[cpscdave]

Brian Douglas's videos are great.

He is the only reason why I passed Modern Control Systems. I'd watch the videos and understand the material. Prof was useless.

 

[rude man]

I think the formula you were given in class is wrong. Even if it works it's completely at variance with every other transform pair I've ever encountered, and I've encountered many.