Section 12: Calculating with Matrices 169

4.Recall the descriptor of the matrix representing A into the display.

5.If the elements of A were entered in the form of AC, press ´ pto transform AC into AP.

6.Press ´>2 to transform AP into Ã.

7.Designate the result matrix; it must not be the same as the matrix representing A.

8.Press ÷; this calculates XP. The values of these matrix elements are placed in the result matrix, and the descriptor of the result matrix is placed in the X-register.

9.If you want the solution in the form XC, press c.

Note that you don't transform BP into .

You can derive the complex elements of the solution X by recalling the elements of XP or XC and combining them according to the conventions described earlier.

Example: Engineering student A. C. Dimmer wants to analyze the electrical circuit shown below. The impedances of the components are indicated in complex form. Determine the complex representation of the currents I1 and I2.

This system can be represented by the complex matrix equation

⎡10 + 200i

−200i⎤⎡I

1

⎡5⎤

− 200i

⎥⎢

= ⎢ ⎥

(200− 30)i⎦⎣I2

0

or

 

AX = B.