Need Help

rajiv

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Need answers for these questions ....
 

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If you need answers to these, you had better start doing something yourself. You aren't going to learn anything by having others do problems for you. And, worse, you give the impression (whether true or not I don't know) that you are not really willing do do anything since you scan the paper in rather than typing the problems yourself. You are, whether you know it or not "distancing" yourself from the problems. You have, for one thing, posted this under "differential equations" when none of the problems have anything to do with differential equations. The first problem you post says "If \(\displaystyle x\begin{bmatrix}2 \\ 3 \end{bmatrix}+ y\begin{bmatrix}1 \\ -1 \end{bmatrix}= \begin{bmatrix}10 \\ 5\end{bmatrix}\). Do you know what that means? Do you know how to multiply a vector by a number? How to add two vectors? If you do then you know that this is the same as \(\displaystyle \begin{bmatrix}2x+ y \\ 3x- y\end{bmatrix}= \begin{bmatrix}10 \\ 5\end{bmatrix}\) which is the same as the pair of equations 2x+ y= 10, 3x- y= 5. Can you not solve those equations? The second problem asks if \(\displaystyle \lambda\in R\), what is \(\displaystyle \lambda I_2\)? This is, again, just a matter of knowing basic definitions. Do you know what \(\displaystyle I_2\) means? Do you know how to multiply a number by a matrix? If you honestly have no idea how to even start these, if you have no idea what these words mean then you are in the wrong class. If you do then you should show us what you do know so we don't have to waste time redoing it.
 
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These exercises are very poorly stated. Shame on the author!

For those, like me, who cannot read the tiny image:

1) If x[2 3]^T + y[-1 1]^T = [10 5]^T, then the values of x and y are...?

2) If \(\displaystyle \lambda\)CR, then \(\displaystyle \lambda\)I_2 is the matrix...?

3) If A = [1 2 3] and B = [2 4 1]^T, then AB = ...?

4) If A = \(\displaystyle \left[\begin{array}\cos(\alpha)&-\sin(\alpha)\\ \sin(\alpha)&\cos(\alpha)\end{array}\right]\), then A + A' = I, then the value of \(\displaystyle \alpha\) is...?

5) Differentiate the equation: p = 4q^(3.2)

6) Differentiate the equation: y = 6x^(-3)

7) Differentiate the equation: y = 12sqrt[x^3] + 8

8) Differentiate the equation: m = (-8)/(v^6) + (v^4)/5 + 1/7

9) Differentiate the equation: y = (2/sqrt[x])^3

10) Differentiate the equation using the standard rules: y = x^9

11) Differentiate the equation: y = 4sqrt[x]

12) [unreadable in original image, plus "the list below" was not provided]

13) Differentiate the equation: y = 5 - (9)/(x^7)

14) Differentiate the equation: s = 14t^3 - (t^2)/6 + 5t - 3
Need answers for these questions ....
Look in the back of the book to find the answers, at least for the odds.

However, if you're wanting assistance in learning how to do these, you'll need first to reply with a clear listing of your efforts so far. ;)

Note: If you are unable to make any start on any of these, then you need way more help than we can here provide. Your best bet, in that situation, would likely be to hire a qualified local tutor, and set aside a couple hours a day for intensive face-to-face instruction. With luck and a lot of hard work, you may be able to catch up to your class in only a few weeks.

Also, I have no idea why these matrix-algebra and Calc-I questions were assigned to you in your post-Calc-III "Differential Equations" course (being the category to which you posted this question). Something seems very odd here....
 
sorry if u found the way i posted 'dumb'

Am really sorry if the way i posted looked funny/disrespecting ... no pun intended ... am no maths student and am being asked these questions for mock promotional exam do help me solving these.

If you need answers to these, you had better start doing something yourself. You aren't going to learn anything by having others do problems for you. And, worse, you give the impression (whether true or not I don't know) that you are really willing do do anything since you scan the paper in rather than typing the problems yourself. You are, whether you know it or not "distancing" yourself from the problems. You have, for one thing, posted this under "differential equatons" when none of the problems have anything to do with differential equations. The first problem you post says "If \(\displaystyle x\begin{bmatrix}2 \\ 3 \end{bmatrix}+ y\begin{bmatrix}1 \\ -1 \end{bmatrix}= \begin{bmatrix}10 \\ 5\end{bmatrix}\). Do you know what that means? Do you know how to multiply a vector by a number? How to add two vectors? If you do then you know that this is the same as \(\displaystyle \begin{bmatrix}2x+ y \\ 3x- y\end{bmatrix}= \begin{bmatrix}10 \\ 5\end{bmatrix}\) which is the same as the pair of equations 2x+ y= 10, 3x- y= 5. Can you not solve those equations? The second problem says if \(\displaystyle \lambda\in R\), what is \(\displaystyle \lambda I_2\). This is, again, just a matter of knowing basic definitions. Do you know what \(\displaystyle I_2\) means? Do you know how to multiply a number by a matrix? If you honestly have no idea how to even start these, if you have no idea what these words mean then you are in the wrong class. If you do then you should show us what you do know so we don't have to waste time redoing it.
 
sorry bout the way i published...

Honestly speaking i have made no progress as i duno any of these ... am not into math as ma subject is totally irrelevant to these problems... i couldn find the solution anywhere so i took my friend's advice to find answers here.. am preparing for my mock promotional exam so came here to get help in solving these. and sorry bout thee way i posted... feel like laughing @ myself but no pun intended as i duno those symbols that u ve added too... couldn find a way to type those questions... sorry for that...

These exercises are very poorly stated. Shame on the author!

For those, like me, who cannot read the tiny image:


Look in the back of the book to find the answers, at least for the odds.

However, if you're wanting assistance in learning how to do these, you'll need first to reply with a clear listing of your efforts so far. ;)

Note: If you are unable to make any start on any of these, then you need way more help than we can here provide. Your best bet, in that situation, would likely be to hire a qualified local tutor, and set aside a couple hours a day for intensive face-to-face instruction. With luck and a lot of hard work, you may be able to catch up to your class in only a few weeks.

Also, I have no idea why these matrix-algebra and Calc-I questions were assigned to you in your post-Calc-III "Differential Equations" course (being the category to which you posted this question). Something seems very odd here....
 
Am really sorry if the way i posted looked funny/disrespecting ... no pun intended ... am no maths student and am being asked these questions for mock promotional exam do help me solving these.

If that is true - why are you trying to find answers to these problems?

What is a "mock promotional exam" anyway" ? why can't you have "mock answers" for "mock exams"?
 
a set of questions tat we work for practice purpose

There are a set of exams which wil help us get promoted along with our work performance... and to our best knowledge we have those questions and out of those a few math questions are included... thou ma major was economics i juz dont want to skip anything... mock is more like an imitation or substitute, esp for practice purposes ... any other that u want to know??? i guess i could ask some 12th grade student! and what is that "why can't you have "mock answers" for "mock exams"?" means??? :mrgreen:

If that is true - why are you trying to find answers to these problems?

What is a "mock promotional exam" anyway" ? why can't you have "mock answers" for "mock exams"?
 
There are a set of exams which wil help us get promoted along with our work performance... and to our best knowledge we have those questions and out of those a few math questions are included... thou ma major was economics i juz dont want to skip anything... mock is more like an imitation or substitute, esp for practice purposes ... any other that u want to know??? i guess i could ask some 12th grade student! and what is that "why can't you have "mock answers" for "mock exams"?" means??? :mrgreen:

So you want to know the answers to these questions - not learn how to do these - so that you can get promoted?
 
wil b better memorizing them :)

eh... i ll juz memorize :( sorry again if u think am being ignorant... but juz want to reap the reward... in a way or other tats the truth i wouldn deny... but as of i really dont think i can sit and learn them in a short time... juz need to memorize asap ... juz being frank and putting them straight forward...

So you want to know the answers to these questions - not learn how to do these - so that you can get promoted?
 
eh... i ll juz memorize :( sorry again if u think am being ignorant... but juz want to reap the reward... in a way or other tats the truth i wouldn deny... but as of i really dont think i can sit and learn them in a short time... juz need to memorize asap ... juz being frank and putting them straight forward...
There is no way you can just memorize this sort of thing. The problems on the test will be different so memorizing these will not help.

I'd concentrate on reviewing what you do know, including the math you already learned for economics.
 
The "funny" (may be sad) part is that the Noble prize in economics is a de facto Noble prize for mathematics.
 
Need the answers!!! :(
No, you do NOT "need the answers". They won't do you any good at all. What you need is to learn how to do the problems yourself and you don't seem to have made any attempt to do that. You learn mathematics by doing mathematics, not by seeing other people do it.
 
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i ll juz memorize
You'll memorize the answers to these particular questions, which will be different from what you'll likely encounter on the "real" test, and without any knowledge of what's going on? How on earth do you think you'll fool anyone with that?

juz want to reap the reward...
You want to "reap the reward" for what? Getting other people to cheat for you? So... you're wanting to be blackballed from your target profession as a known liar?

i really dont think i can sit and learn them in a short time...
In other words, you're not qualified for the promotion or the position. You want our help to perpetrate a fraud.

Frankly, I'm offended that you presume to think so little of my character.

To be fair, however, this member has, in the past, generally been quite willing to provide what you seek. Please message him privately, and leave the rest of us out of this. Thank you.
 
sorry again for posting the thread in such a way

There are a set of questions and most are related to Information and Technology. am sure i can do well... i know am looking for shortcuts in maths ... but am juz in a hurry and... i know i can justify my stance ... really sorry for the way i posted this thread... juz that am helpless ... sorry again...

You'll memorize the answers to these particular questions, which will be different from what you'll likely encounter on the "real" test, and without any knowledge of what's going on? How on earth do you think you'll fool anyone with that?


You want to "reap the reward" for what? Getting other people to cheat for you? So... you're wanting to be blackballed from your target profession as a known liar?


In other words, you're not qualified for the promotion or the position. You want our help to perpetrate a fraud.

Frankly, I'm offended that you presume to think so little of my character.

To be fair, however, this member has, in the past, generally been quite willing to provide what you seek. Please message him privately, and leave the rest of us out of this. Thank you.
 
Fine.. teach me then :) i really duno much in maths ... am no math student .. leave aside wat i asked here... teach me then.. i ll try to solve em myself.. thanks in advance.

No, you do NOT "need the answers". They won't do you any good at all. What you need is to learn how to do the problems yourself and you don't seem to have made any attempt to do that. You learn mathematics by doing mathematics, not by seeing other people do it.
 
Fine.. teach me then :) i really duno much in maths ... am no math student .. leave aside wat i asked here... teach me then.. i ll try to solve em myself.. thanks in advance.

This is NOT a site where we teach math.

This is a site where we try to help students who have shown some effort.

If you want to learn math - you need to go to school or start with a site like:

http://www.purplemath.com/modules/index.htm

Find where you can start and continue.

If you get stuck on a particular problem - come beck here and show your work on the problem (or concepts) and only then we can help you.
 
Just went through the thread looking for work to help with - the only work done yet seems to be HallsofIvy's initial response, showing in some detail how to interpret the first question. Good work, HoI! Now how about a response from rajiv... did you even follow through on one question?
 
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