View of /trunk/rochester_problib/setGeometry3Conics/ur_geo_3_23.pg

    1 ##DESCRIPTION
    2 ## circle with center in Q2, leading coefficient 1
    3 ##ENDDESCRIPTION
    4 
    5 ##KEYWORDS('analytic geometry', 'circle')
    6 
    7 DOCUMENT();        # This should be the first executable line in the problem.
    8 
    9 loadMacros(
   10 "PG.pl",
   11 "PGbasicmacros.pl",
   12 "PGchoicemacros.pl",
   13 "PGanswermacros.pl",
   14 "PGauxiliaryFunctions.pl"
   15 );
   16 
   17 TEXT(&beginproblem);
   18 $showPartialCorrectAnswers = 1;
   19 
   20 $k = random(3,9,1);$k2=2*$k;
   21 $h = random(3,9,1);$h2=2*$h;
   22 $r = random(1,1.4*sqrt($k**2+$h**2),1);
   23 $c = $k**2+$h**2-$r**2;
   24 
   25 TEXT(EV2(<<EOT));
   26 \( x^2+y^2+$h2 x-$k2 y +$c=0 \) is the equation of a circle with center \( (h,k) \) and radius \( r \) for:$BR
   27 $BR
   28 \( h= \)\{ans_rule(10) \}
   29 $BR
   30 EOT
   31 
   32 $ans = -$h;
   33 &ANS(std_num_cmp($ans));
   34 
   35 TEXT(EV2(<<EOT));
   36 and$BR
   37 \( k= \) \{ans_rule(10) \}
   38 $BR
   39 EOT
   40 
   41 $ans =  $k;
   42 &ANS(std_num_cmp($ans));
   43 
   44 TEXT(EV2(<<EOT));
   45 and$BR
   46 \( r= \) \{ans_rule(10) \}
   47 $BR
   48 EOT
   49 
   50 $ans =  $r;
   51 &ANS(std_num_cmp($ans));
   52 ENDDOCUMENT();        # This should be the last executable line in the problem.