Important:
Removing the battery will cause all of the calculator’s memory
contents to be deleted.
1. Press
(OFF) to turn off the
calculator.
• To ensure that you do not
accidentally turn on power
while replacing the battery,
slide the hard case onto the
front of the calculator.
2. As shown in the illustration,
remove the cover, remove the
battery, and then load a new
battery with its plus (+) and minus
(−) ends facing correctly.
3. Replace the cover.
Screw
Screw
fx-570AR X
Screw
fx-991AR X
4. Initialize the calculator:
(RESET)
(Initialize All)
(Yes).
• Do not skip the above step!
Technical Information
Calculation Range and Precision
Calculation Range
±1 × 10
-99
to ±9.999999999 × 10
99
or 0
Number of Digits for
Internal Calculation
15 digits
Precision
In general, ±1 at the 10th digit for a single
calculation. Precision for exponential display is
±1 at the least significant digit. Errors are
cumulative in the case of consecutive
calculations.
Function Calculation Input Ranges and Precision
Functions
Input Range
sin
x
cos
x
Degree
0
≦
|
x
| < 9 × 10
9
Radian
0
≦
|
x
| < 157079632.7
Gradian
0
≦
|
x
| < 1 × 10
10
tan
x
Degree
Same as sin
x
, except when |
x
| = (2
n
−1) × 90.
Radian
Same as sin
x
, except when |
x
| = (2
n
−1) ×
π
/2.
Gradian
Same as sin
x
, except when |
x
| = (2
n
−1) ×
100.
sin
-1
x
, cos
-1
x
0
≦
|
x
|
≦
1
tan
-1
x
0
≦
|
x
|
≦
9.999999999 × 10
99
sinh
x
, cosh
x
0
≦
|
x
|
≦
230.2585092
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