HP HP-15C

154 Section 4: Using Matrix Operations
Keystrokes
3 | ENTER ||T|| DIM |[A]
Display
3.0000 Dimensions A to 3 X 3.
3.0000 SetsRoandRitol.
0.0000 Enters au.
1.0000 Enters a12.
StSTOJS 3.0000 Enters a32.
4|STO|rA~| 4.0000 Enters a33.
[A] 0.8660 Calculates ratio—too
large.
Again, too large.
Again, too large.
Again, too large.
Again, too large.
Negligible ratio.
Recalls au = A^.
Recalls a12.
Recalls a13.
Recalls a21.
Recalls a22 = X2.
Recalls a23.
Recalls a31.
Recalls a32.
Recalls a33 = X3.
Deactivates User mode.
In the new coordinate system the equation of the quadratic surface
is approximately
0.2304
0.1039
0.0060
3.0463
5.8257
0.8730
9.0006
2.0637
9.0006
9.3429
1.0725
2.0637
1.0725
6.8730
6.8730
-05
-10
-10
-09
-10
-11
-09
-09
-09
-0.87302?
+ 6.87302 = 7.
This is the equation of a hyperbolic cylinder.
Eigenvectors of a Symmetric Real Matrix
As discussed in the previous application, a real symmetric matrix
A has real eigenvalues X1; X2, ... and corresponding orthogonal
eigenvectors qb q2, ... .