TI-84 gives me domain error

[Shadow Conception]

So today during our final exam in AlgII, I made a 2x2 matrix. I then took this matrix ([A]), and put it to the -1st power, to find the inverse. So, my command basically looked like this:

[A]^(-1)

This gave me a domain error. At home, I do exactly this with the TI-89 Titty, and it works.

It turns out, on the TI-84, to invert a matrix, you have to use the "x^-1" button, shown here right underneath the big MATH button. Stupidly enough, that was also the MATRIX button I had to use to create a matrix, I just didn't notice the big fat "x^-1" sitting there as well.

Is there a reason why my method didn't work on the TI-84?

 

[haffey]

Dunno. I have a TI-84 Plus and that's how I was always taught to do inverse matrices. As a general rule, the opposite function is generally the same key, just with 2nd pressed. Like ^2 and square root.