Question

Find the determinant of the following matrix. can someone please explain to me how to do this?
P=[ 1 2 -1
4 0 1
1 -2 3

Answer 1

\[ \large \begin{vmatrix}
a & b & c\\ d & e & f\\ g &h & i
\end{vmatrix}=aei+bfg+cdh-(ceg+afh+bdi) \]

Answer 2

so would it be 10-(-15)?

Answer 3

omg, that will work... kinda hard to remember though
I was wondering how somebody was going to explain this.
It is easy (even fun) to explain the patterns in person, hard to explain through text.

Answer 4

i agree @EulerGroupie

Answer 5

I mean 10-(22)?

Answer 6

second one... yes

Answer 7

yes.