Matrix Multiplication and Evaluation: B & A

[James09]

where possible evaluate the following

B A

B= (12 14 15 ) A= ( 1.2 1 )
( 1 1 12 ) (-0.6 0.8 )
( -0.1 -0.9 )

 

[micromass]

What did you try already?? If we know where you're stuck, then we'll know how to help...

 

[James09]

3B - 2E

12 14 15 X3 36 3
1 1 12 28 3
45 36

13 12 17 X2 26 6
3 19 -8 24 38
34 -16

26 6 36 3
24 38 + 28 3
34 - 16 45 36


62 9
52 41
79 20

thats one I done earlier am I doing it the correct way??

 

[micromass]

3B - 2E

12 14 15  X3       36   3
1   1  12            28    3
                        45   36

13 12 17   X2      26   6        
3  19 -8             24   38
                       34    -16

26  6                36  3
24 38     +         28  3
34 - 16             45 3662  9
52  41
79 20

thats one I done earlier am I doing it the correct way??

No, when calculating 3B or 2E, you seem to replace columns with rows and vice versa. I don't know why you do that. Here's an example

$$4\left(\begin{array}{cc} 1 & 2\\ 3 & 4\\ 5 & 6 \end{array}\right)=\left(\begin{array}{cc} 4 & 8\\ 12 & 16\\ 20 & 24 \end{array}\right)$$

 

[James09]

Thanks for the help lads

I've got a sharp El-W531 Calculator how to you do to the power of a minus number for example 5 * 8 to the power of -3?

And Can someone tell me what D is in base 16?



Q. A color is represented by the following string #10FAE2. Explain the meaning of this?

The answer is given as

Red 1016 = 16
Green FA16=250
Blue E216=226

Can someone tell me how that answer is given?



Write the first four terms of the following sequences?

(i) an=4nsquared -2, n more than or equal to 1
(ii)an=6an-1 + 1,n more than or equal to 1 where a1 = 5

(b)
The first term of the geometric sequence is 12.5 and the common ratio is 0.4

(i) Write out the first four terms of the sequence
(ii)Write out the formula for the nth term of this sequence
(iii)What is the 12th term of this sequence?
(iv)Write out the formula for the sum of the first n terms of this sequence.
(v)What is the sum of the first 8 te

 

[Nylex]

And Can someone tell me what D is in base 16?

This isn't too difficult. Base 16 means you have values in the range 0-15, each of which is represented as a single digit. After 9, we'd have to use two digits to represent the numbers, so we use letters instead (starting with A). Can you now work out what D is?

Edit: Your questions seem to be quite distinct, so you should probably be using separate threads for each..

 

[James09]

this isn't too difficult. Base 16 means you have values in the range 0-15, each of which is represented as a single digit. After 9, we'd have to use two digits to represent the numbers, so we use letters instead (starting with a). Can you now work out what d is?

a=10
b=11
c=12
d=13
e=14
f=15

?

 

[Nylex]

Yes, that's correct.

 

[James09]

Yes, that's correct.

so for example is i was given

1FF2 = it would be 11515216

I don't suppose you know how to solve the rest of the problems?

 

[Nylex]

so for example is i was given

1FF2 = it would be 11515216

I'm not exactly sure what you mean by "11515216". You know that each digit represents a multiple of a power of the base, yes? For example, in decimal (base 10),

\begin{equation}
123 = 1 \times 10^2 + 2 \times 10^1 + 3 \times 10^0
\end{equation}

I don't suppose you know how to solve the rest of the problems?

You're going to need to show evidence of what you've tried already and what you don't understand. The first question seems to give you the relation between the $n$th term and $n$, so it shouldn't be too hard. Presumably, you've also seen a geometric series before.