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gibson:teaching:fall-2013:math445:hw1

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gibson:teaching:fall-2013:math445:hw1 [2013/09/05 11:36]
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gibson:teaching:fall-2013:math445:hw1 [2013/09/06 11:55] (current)
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 +Selected problems from Attaway 3rd edition, chapters 1 and 2.
  
 **Problem 1:** Create the following vectors twice, once using **linspace** and once using the colon operator. **Problem 1:** Create the following vectors twice, once using **linspace** and once using the colon operator.
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 **Problem 3:** Given a vector //v// of arbitrary length, write an expression that evaluates to the odd-numbered elements of //v//. Test your expression on vectors //v// of both even and odd length. **Problem 3:** Given a vector //v// of arbitrary length, write an expression that evaluates to the odd-numbered elements of //v//. Test your expression on vectors //v// of both even and odd length.
  
-**Problem 4:** Given a vector //v// of arbitrary length, write assignment statements that store the first half of //v// in a vector //v1// and the second half in a vector //v2//. Make sure your assignment statements work for //v// of both even and odd length. Hint: use a rounding function such as **fix**.+**Problem 4:** Given a vector //v// of arbitrary length, write assignment statements that store the first half of //v// in a vector //v1// and the second half in a vector //v2//. Make sure your assignment statements work for //v// of both even and odd length. ​
  
 **Problem 5:** Create a 4 x 2 matrix of all zeros and store it in a variable. Then replace the second row of the matrix with a 3 and a 6.  **Problem 5:** Create a 4 x 2 matrix of all zeros and store it in a variable. Then replace the second row of the matrix with a 3 and a 6. 
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   10 > 5 > 2   10 > 5 > 2
   ​   ​
-**Problem 8: The value of $\pi^2/6$ can be approximated by the sum of the series+**Problem 8:** The value of $\pi^2/6$ can be approximated by the sum of the series
  
 <​latex>​ <​latex>​
-1 + \frac{1}{3} \frac{1}{9} + \frac{1}{27} ​\frac{1}{81} + \ldots+1 + 1/2^2 + 1/3^2 + 1/4^2 + \ldots
 </​latex>​ </​latex>​
  
 Write a one-line Matlab expression that evaluates the sum for the first $n$ terms. Test it for a few values of $n$ and compare to $\pi^2/6$. Write a one-line Matlab expression that evaluates the sum for the first $n$ terms. Test it for a few values of $n$ and compare to $\pi^2/6$.
 +
 +**Problem 9:** A vector //v// stores hours worked and hourly wages sequentially for a number of employees. For example
 +
 +<​code>​
 +  v = [33 10.5 40 18 20 7.5]
 +</​code>​
 +
 +would specify three employees, the first working for 33 hours at %%$10.50/​hr%%,​ the second 40 hours at %%$18/hr%%, etc. For an arbitrarily long //v//, write code that would separate //v// into an //h// vector of hours worked and a //r// vector of hourly wage rates, and then compute a //w// vector of wages owed to each employee. Do this as compactly as possible. ​
 +
 +
 +**Problem 10:** Evaluations at a university are scored 1-5, bad to good. However the evaluation forms mistakenly say that 1-5 is good to bad. So the computer program written to analyze evaluations must "​reverse"​ all the evaluation scores. That is,
 +
 +  evals = [5 3 2 5 5 4 1 2]
 +  ​
 +should really be
 +
 +  evals = [1 3 4 1 1 2 5 4]
 +  ​
 +Write Matlab code that will reverse an arbitrary //eval// vector to the correct 1-5 scale.  ​
gibson/teaching/fall-2013/math445/hw1.1378406168.txt.gz · Last modified: 2013/09/05 11:36 by gibson