Casio FX-1000f vs Casio FX-5000f

[Mjim]

According to ledudu, it's just the addition of hyperbolic functions (and their inverse):
https://casio.ledudu.com/pockets.asp?type=154&lg=eng

I'm kind of curious as to why the addition of hyperbolic function was such a big feature at the time that they changed the shape of the calculator (The 5000F is a flatter calculator) and gave it a new model name.