View of /trunk/NationalProblemLibrary/Rochester/setAlgebra16FunctionGraphs/c0s1p1/c0s1p1.pg

    1 #DESCRIPTION
    2 #KEYWORDS('function', 'graph', 'linear', 'increasing/decreasing')
    3 #  Goal: Identify that a line represents an increasing, decreasing or constant function
    4 #  or is not the graph of a function (when the line is vertical).
    5 #  Contains an introduction explaining the importance of linear (affine) functions.
    6 #ENDDESCRIPTION
    7 
    8 DOCUMENT();        # This should be the first executable line in the problem.
    9 
   10 loadMacros("PG.pl",
   11            "PGbasicmacros.pl",
   12            "PGchoicemacros.pl",
   13            "PGanswermacros.pl",
   14 "PGauxiliaryFunctions.pl");
   15 
   16 $pictSet=&random(1,3,1);  #there are three sets of graphs
   17 
   18 $pictNum=&random(1,4,1);  #each set has 4 graphs the numbers are below
   19 
   20 @pictID = (
   21 "1-55141.gif",
   22 "1-79226.gif",
   23 "1-75352.gif",
   24 "1-65474.gif",
   25 "2-96187.gif",
   26 "2-11287.gif",
   27 "2-68382.gif",
   28 "2-63428.gif",
   29 "3-44144.gif",
   30 "3-69221.gif",
   31 "3-18387.gif",
   32 "3-55459.gif"
   33 );
   34 
   35 sub pictIndex{    # this gives offsets into @pictID -- I was too laxy to do multidimensional arrays
   36   my ($i,$j)=@_;
   37   return(($i-1)*4+$j-1 )
   38   }
   39 
   40 @question = ();
   41 @answer =();
   42 
   43 TEXT(beginproblem(),
   44  qq!The simplest functions are the linear (or affine) functions ---
   45   the functions whose graphs are
   46  a straight line. They are important because many functions (the so-called
   47  differentiable functions) ${LQ}locally$RQ look like straight lines.
   48   (${LQ}locally$RQ means that
   49  if we zoom in and look at the function at very powerful magnification
   50  it will look like a straight line.)  $PAR
   51  !,
   52  "Enter the letter of the graph of the function which corresponds to
   53    each statement. $BR"
   54  );
   55 
   56 qa(~~@question,~~@answer,
   57 "The graph of the line is increasing",
   58 @pictID[&pictIndex($pictSet,1)],
   59 "The graph of the line is decreasing",
   60 @pictID[&pictIndex($pictSet,2)],
   61 "The graph of the line is constant",
   62 @pictID[&pictIndex($pictSet,3)],
   63 "The graph of the line is not the graph of a function",
   64 @pictID[&pictIndex($pictSet,4)],
   65 );
   66 
   67 @slice = 0..3;              # select an ordered subset of the questions and answers
   68 @shuffle = &shuffle(scalar(@slice));    # create a permutation of the right length
   69 @images =  @answer[@slice[@shuffle]];   # create a permuted list of the answers
   70 @captions =@ALPHABET[0..3];             # the caption letters are always in order
   71 
   72 TEXT(
   73 &match_questions_list(@question[@slice]),
   74 &imageRow(~~@images,~~@captions)
   75 );
   76 @ans = @ALPHABET[&invert(@shuffle ) ];
   77 ANS(str_cmp(  [ @ans ] ) );
   78 
   79 ENDDOCUMENT();        # This should be the last executable line in the problem.