Casio fx-991ES PLUS User Manual

Using Calculation Modes
Complex Number Calculations
(CMPLX)
To perform complex number calculations, first press
(CMPLX) to
enter the CMPLX Mode.
You can use either rectangular coordinates (a+bi) or polar coordinates
(r∠θ) to input complex numbers.
Complex number calculation results are displayed in accordance with the
complex number format setting on the setup menu.
Example 1: (2 + 6i) ÷ (2i) = 3 - i (Complex number format: a+bi)
2 6 (i) 2 (i) 3-i
Example 2: 2∠45 = √2 + √2i (MthIO-MathO) (Angle unit: Deg)
(Complex number format: a+bi)
2 (∠) 45
√2+√2i
Example 3: √2 + √2i = 2∠45 (MthIO-MathO) (Angle unit: Deg)
(Complex number format: r∠θ)
2 2 (i)
2∠45
Note
• If you are planning to perform input and display of the calculation result in polar
coordinate format, specify the angle unit before starting the calculation.
• The θ value of the calculation result is displayed in the range of -180° < θ ≦ 180°.
• Display of the calculation result while Linear Display is selected will show a and bi (or r
and θ) on separate lines.
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Casio fx-991ES PLUS Specifications

General

Type	Scientific
Cover	No
Form factor	Desktop
Control type	Buttons
Product color	Gray
Digits	15 digits
Display type	Dot-matrix
Display resolution	96 x 31 pixels
Display number of lines	10 lines
Storage media type	Not available
Battery life	3 year(s)
Battery type	LR44
Power source	Battery/Solar
Number of batteries supported	1
Symbolic notation	Square root
Conversion between	Decimal, Fraction, Percent
Convert angles from degrees to	Gradian, Radian
Random number/integer generator	Yes

Weight and Dimensions

Depth	162 mm
Width	80 mm
Height	11.1 mm
Weight	95 g