HP HP-28S - Page 76

For other functions, the symbolic constant 'IT produces an expression
containing
'IT. If you force a real-number result, the calculator uses the
12-digit approximation.
To demonstrate the difference between 3.14159265359 and 'IT, calcu-
late
the sine of each.
Put I 'IT I in level 1 .
• GJ I ENTER!
Although this object looks like a name, it's actually an expression
with a single term, the symbolic constant 1r.
Force a real-number result using .... NUM (to number)
.1 +NUM! 3:
2:
1: 3.14159265359
BmlmmaallIDllllDmmJ
The 12-digit approximation to 7r (3.14159265359) is returned to level
1.
Calculate the sine of the approximation to 7r.
SIN
3:
2:
1: -2. 06761537357E-13
BmlmmaallIDllllDmmJ
The result (-2.06761537357 x 10-
13
)
isn't exactly 0 because the ar-
gument (3.14159265359) isn't exactly 7r.
Now calculate the sine of 7r.
3:
2: -2.06761537357E-13
1: 0
BmlmmaamalllDmmJ
The SIN function recognizes the symbolic constant 7r and returns the
exact result (0).
5: Real-Number Functions 75
I