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Matrix Operations 762 Views
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Description:
Your one video for all things matrix operations.
Transcript
- 00:04
Matrix Operations a la Shmoop you look at Gilligan Huffington III CEO of Handbags.com [man at white board]
- 00:10
had a great earnings report in January and February with everyone feeling pretty good [doctors celebrating in meeting]
- 00:15
about the bullish market and the economy doing better as a whole people are spending money
- 00:19
like money is growing on trees finally being a great businessman that Gilligan is he wants [kid holding a fan of money]
- 00:25
to project how well his company will do in March and April all together he estimates [man chases pig]
Full Transcript
- 00:31
that in March customers will probably buy half the amount of things they bought in January
- 00:36
but they will will buy the same amount in April as they did in February here's out data
- 00:41
for how many full price and discounted handbags watches and shoes he sold in January and February
- 00:47
in matrix format why aren't we using tables? [matrices]
- 00:50
well actually matrices are a good way to organize our data when we want to perform operations
- 00:56
with them such as adding them or multiplying numbers to the data first lets figure out
- 01:01
what the March and April data look like in March Gilligan estimates that customers will
- 01:07
probably buy half the amount of things they bought in January so we can just take January's
- 01:12
data and multiply the matrix by one half this is called multiplying by a scalar where scalar
- 01:18
is just another name for a number in essence we will just multiply each number in the matrix
- 01:24
by one half to get nine six five seven two and three those numbers are for Gilligan's
- 01:30
purposes millions in April Gilligan estimates that the customers will buy the same amount
- 01:36
in April as they did in February so we can just keep February's data the same Gilligan
- 01:42
wants to find the total of March and April's data so we'll have to add the two matrices
- 01:48
not that because the dimensions of both of these matrices are the same we can add them [teacher at white board in front of students]
- 01:54
if they weren't we wouldn't be able to to add two matrices we can just add each corresponding
- 01:59
pair of numbers we get nine plus eight equals seventeen six plus seven is thirteen five
- 02:06
plus six is eleven seven plus two is nine two plus nine is eleven and three plus four
- 02:12
is seven out final answer seventeen thirteen eleven nine eleven and seven looks like Gilligan's
- 02:19
gonna have another great two months [money showering over man]
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