Log/matrix/calc/algebra/probability/retarded question.

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In summary, the conversation was about a strange extended-response exercise that combined various topics. The first row was easy, but the second row, first column was challenging. The vertical lines in A22 represent absolute value signs, and in this case, they are not necessary. For A21, the meaning of Pr(A) and Pr(A') was discussed, with the conclusion that they represent the probability of an event occurring and not occurring, respectively. The solution to the exercise involved using the obvious loge ex= x for A22 and interpreting \left(\frac{d}{dx}(x^2)\right)^0 as "raised to the 0-th power" for A21. The conversation also touched on the topic of probabilities adding up
  • #1
morson
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Homework Statement



In the picture.

Homework Equations





The Attempt at a Solution



This is a really strange question. It's an extended-response exercise. I don't think it'd look pretty using the TeX thing, so I drew it in Paint. It combines all the topics we've done so far. Row 1 is easy. Row 2, column 1, I have no clue how to do. I'm not sure about the straight lines on the log in the bottom right, either.

http://img260.imageshack.us/img260/9584/blahgm8.png
 
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  • #2
In A22, the vertical lines are absolute value signs, which basically means that you take the positive value of what's inside them. In general, these are needed since the logarithm function is only defined for postiive real numbers. However, in this case, the argument is postive, and they are not really needed.

For A21, I'm afraid I don't really know what the Pr(A) and Pr(A') means. [Do you have the definition of Pr(A')? It looks like it must be equal to -Pr(A)]
 
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  • #3
Pr(A) and Pr(A'), I'm sure, are "Probabiliity that event A occurs" and "Probability even A does not occur". It's a bit annoying that they also use A to represent the entire matrix, but, hey, it's a silly exercise to begin with! Whatever "event A" is, Pr(A)+ Pr(A') is easy trivial!

Oh, and for A22 use the obvious loge ex= x.

The problem I have is A21:
[tex]\left(\frac{d}{dx}(x^2)\right)^0[/tex]

I would interpret that as the derivative evaluated at x= 0 but then the answer is not what you give! The derivative evaluated at x= 1/2 will give that answer.

Finally, this is surely not "precalculus"!
 
  • #4
I'm pretty sure that's "raised to the 0-th power".
 
  • #5
Ah, that makes sense!
 
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  • #6
Ah, I see, so the probabilities added up is 1?
 
  • #7
Yes, of course.
 

FAQ: Log/matrix/calc/algebra/probability/retarded question.

What is the difference between logarithmic and exponential functions?

Logarithmic and exponential functions are inverse of each other. In a logarithmic function, the base is a constant and the exponent is the variable, while in an exponential function, the base is the variable and the exponent is a constant. The main difference is that logarithmic functions are used to solve for the exponent, while exponential functions are used to solve for the base.

How can matrices be used in real-life applications?

Matrices are used in a variety of fields, such as engineering, economics, and computer science. In engineering, matrices are used for analyzing structures and solving systems of equations. In economics, matrices are used for analyzing market trends and forecasting. In computer science, matrices are used for image processing and data compression.

What is the purpose of calculus?

Calculus is used to analyze and model continuous change. It is used to solve problems related to rates of change, optimization, and area/volume calculations. It is also the foundation for many other fields of mathematics, such as physics and engineering.

How do algebraic equations help in problem-solving?

Algebraic equations help in problem-solving by representing relationships between variables and allowing us to solve for unknown values. They can be used to solve real-world problems in various fields, such as finance, science, and engineering.

What is the difference between probability and statistics?

Probability is the branch of mathematics that deals with the likelihood of events occurring. It is used to predict the outcomes of experiments or events. Statistics, on the other hand, is the study of data collection, analysis, interpretation, and presentation. It is used to make informed decisions and draw conclusions about a population based on a sample of data.

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