Program Instructions:

1.Key in the program routines; press ‡when done.

2.Press XA to input coefficients of matrix and column vector.

3.Key in coefficient or vector value (A through L) at each prompt and press g.

4.Optional: press XD to compute determinant of 3 3 system.

5.Press XI to compute inverse of 3 3 matrix.

6.Optional: press XA and repeatedly press gto review the values of the inverted matrix.

7.Press XM to multiply the inverted matrix by the column vector and to see the value of X. Press gto see the value of Y, then press gagain to see the value of Z.

8.For a new case, go back to step 2.

Variables Used:

 

A through I

Coefficients of matrix.

J through L

Column vector values.

W

Scratch variable used to store the determinant.

X through Z

Output vector values; also used for scratch.

i

Loop–control value (index variable); also used for

 

scratch.

Remarks:

For 2 2 solutions use zero for coefficients C, F, H, G and for L. Use 1 for coefficient I.

Not all systems of equations have solutions.

Example:

For the system below, compute the inverse and the system solution. Review the inverted matrix. Invert the matrix again and review the result to make sure that the original matrix is returned.

23X + 15Y + 17Z = 31

8X + 11Y – 6Z = 17

4X + 15Y + 12Z = 14

15–18Mathematics Programs