Polar Form - Casio fx-9860GII Instructions Manual

From the menu, choose Polynomial and press
You will see the dialog box as shown on the right.
Choose equations of degree 3 and press
Another dialog box opens for you to enter the equation.
The general form of the quadratic equation is aX
so we enter the coeffi cients in a, b, c and d.
(–)
Be sure to use the key to enter the negative values.
Press EXE after each value.
Press F1 SOLV and the calculator will fi nd the roots of the equation.
The solutions are,
x = 1.5, x = 3 + 2i and x = 3 – 2i.

1.12 Polar form

The GDC displays complex numbers in either Cartesian form (z = x + yi ) or
in a modulus, argument form r∠ – see 1.11 for how to fi nd the modulus and
argument of a complex number expressed in Cartesian form.
Example 15
i Change 2 + 2i to polar form.
2
ii Change 3cis to Cartesian form.
3
Press MENU . You will see the dialog box as shown on the right.
Choose 1: RUN·MAT and press
Complex calculations are entered the same way as you would
enter a real expression.
To enter the imaginary number symbol i press
i Enter (2 + 2i ) and then press
Press EXE
The result is 2 2 cos
© Oxford University Press 2012: this may be reproduced for class use solely for the purchaser's institute
F2
F2
.
EXE .
SHIF T
OPTN F3
| CPLX |
i sin or 2 2 cis
4 4 4
.
If there are previous
equations in the memory,
EXIT
press until you return
to this menu.
3 2
+ bX + cX + d = 0
i.
r ∠ θ
F6 F3
|
Casio fx-9860GII
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Continued on next page
Using a graphic display calculator 17