>> format hex
>> 1

ans =

   3ff0000000000000

>> -1

ans =

   bff0000000000000

>> 2

ans =

   4000000000000000

>> 3

ans =

   4008000000000000

LARGEST NUMBER?

>> format long e
>> hex2num('7fffffffffffffff')

ans =

   NaN

WE SEE LARGEST EXPONENT VALUE IS RESERVED FOR SPECIAL CONDITIONS 
("NaN" and "Inf": "Not a Number" and "Infinity")

>> 0/0
Warning: Divide by zero.

ans =

   NaN

>> 1/0
Warning: Divide by zero.

ans =

   Inf


REDUCE EXPONENT BY 1:

>> hex2num('7fefffffffffffff')

ans =

    1.797693134862316e+308

>>