Charlie's (Jan28)

This week we did matrices stuff.
we added, subtracted, multiplied, & divided them.
(we started doing the ALEKS.com thing online)

we did some cramer guy's rule too.
cramers rule:
dx/d = x
dy/d = y
dz/d = z
dx [answer y z ...]
dy [x answer z ...]
d [x y z ...]

we also learned how to do inverses.
to find the inverse:
A^-1 = 1/the determinant of A
to find the determinant:
-[a b] = ad - bc
[c d]

Example ~inverse~:
1) find the inverse of [3 2]
_______________[1 6]
3 x 6 - 2 x 1 = 18 - 2 = 16
1/16
so the inverse of [3 2]
____________[1 6] is 1/16