On the 89, the general input for a matrix is:
Originally Posted by slapmaxwell1
where the semicolons are used to end a row, and this would return
on your calculator screen. If you want to compute the determinant, then you should use
and so on for other types of operations.
So for your example, to find the eigenvalues, you could do it all in one input:
I put csolve just in case the eigenvalues are complex.
csolve(det([3-x,-5;3/4,-1-x]) = 0,x)
I hope this helps!
P.S. You need to make sure that nothing is stored in the variable you're using! Otherwise you'll get an error!! The easiest way to fix that would be to use DelVar "list of variable(s)"