Thursday sept,24/09 lesson was on Matrices

so i took the time to paint and i hope it helps some what!! :)

basically we learned all the basics:

the dimensions r figured out by getting the rows and then columns

ex the top left box's dimensions r

x= 3x5 and **when doing this make sure to always put ROWS FIRST**

Element is just 1 of the numbers in the matrix just like i showed the 2 in the top left matrix is just 1 element out of the 15 in the matrix

Ex 1 questions:

B: it asks 4 the dimensions so we count the rows first then we count the columns and we get A=4x3, 4 rows and 3 columns

C: asks 4 the # of elements which is found by just finishing the dimensions part, A=4x3 so the element amount would be 4x3=12, 12 is the amount of elements in the matrix

D: asks us to find what the element is in A42, so we go to row 4 and column 2 and the match is 68

E: asks us what the postions of element 50 is, it is in row 2 and column 3 so answer is A23

Ex 2 add/subtracting:

this just shows us how to add and subtract matrix together

RULE ** Can only add or subtract if they have the same dimensions**

(look to pic 4 more info)

Ex 3 Scalar - single #:

example 3 shows us how to multiply a matrix,

the prices in the matrix are in american and we need to find them out in canadian so we times it by the exchange rate of 1.46 and it gives us the prices we would have to pay in canadian

anyways i think that is all good luck to the rest of u