Casio fx-991ES PLUS - Manual (Page 30)

E-29
EQN Mode Calculation Examples
x + 2 y = 3, 2 x + 3 y = 4
(EQN)(a
n
X + b
n
Y = c
n
)
1 2 3
2 3 4
(X=) –1
A (Y=) 2
x – y + z = 2, x + y – z = 0, – x + y + z = 4
(EQN)(a
n
X + b
n
Y + c
n
Z = d
n
)
1 1 1 2
1 1 1 0
1 1 1 4
(X=) 1
A (Y=) 2
A (Z=) 3
x 2 + x +
4
3
= 0
(EQN)(aX 2 + bX + c = 0)
1 1 3 4 (X
1
=)
1
2
+ –
'
2
2
i
A (X
2
=)
1
2
– –
'
2
2
i
x 2 – 2
'
2 x + 2 = 0
(EQN)(aX 2 + bX + c = 0)
1 2 (X=) '
2
x 3 – 2 x 2 – x + 2 = 0
(EQN)(aX 3 + bX 2 + cX + d = 0)
1 2 1 2 (X
1
=) –1
A (X
2
=) 2
A (X
3
=) 1
Matrix Calculations (MATRIX)
Use the MATRIX Mode to perform calculations involving matrices of up to 3
rows by 3 columns. To perform a matrix calculation, you first assign data to
special matrix variables (MatA, MatB, MatC), and then use the variables in
the calculation as shown in the example below.
To assign
2 1
1 1
to MatA and
2 –1
–1 2
to MatB, and then perform
the following calculations: ×
2 1
1 1 2 –1
–1 2
(MatA×MatB),
+
2 1
1 1 2 –1
–1 2
(MatA+MatB)
Math Math
Math Math
1 1