** Using WeBWorK **

1) Any idea on how would one test whether the "alttext" for the graph
in the problem below is working? (Here at UM they are very concerned about accessibility issues).
2) I'm not sure how to interpret the error (see attachment)
I got when "testing the randomization" of the following problem:

# DESCRIPTION
# Recognizing values of the parameters k and p from the graph of y=k x^p (with p<0)
# ENDDESCRIPTION
#Right now stored at MAA-PREP2015
# Homework/Workshop3/Souza/problem4.pg
## DBsubject(’Precalculus’)
## DBchapter(’’)
## DBsection(’’)
## Date(’mm/dd/15’)
## Level(’’)
## Keywords(’’)
## Author(’Regina Souza’)
## Institution(’University of Montana, Missoula’)
## TitleText1(’Functions Modeling Change’)
## EditionText1(5)
## AuthorText1(’Connally’)
## Section1(11.1)
## Problem1()

DOCUMENT();
loadMacros("PGstandard.pl",
"MathObjects.pl",
"PGgraphmacros.pl",
"parserPopUp.pl",
"PGML.pl",
"PGcourse.pl");
Context("Numeric");
#Context()->variables->add(t => "Real");
TEXT(beginproblem());
$showPartialCorrectAnswers = 1;
$refreshCachedImages = 1;
Context("Numeric");
$pixels = 200;
# Create the canvas
$gr = init_graph(-1,-1,6,6, # xmin, ymin, xmax, ymax
axes=>[0,0], grid=>[7,7], size=>[$pixels, $pixels]);
$gr -> lb('reset'); # remove default labels
# axes labels
$gr->lb( new Label(5.5,0,'x', 'black', 'center', 'bottom'));
$gr->lb( new Label(0.1,5.5,'y', 'black', 'left', 'middle'));
# axes labels
foreach my $i (1..5) {
$gr->lb( new Label($i,0, $i, 'black', 'center', 'top'));
$gr->lb( new Label(-0.1,$i, $i, 'black', 'right', 'middle'));
}
# randomize the graph
$c = random(2,4,0.5);
# plot a function
$f = Formula("$c/x");
add_functions($gr, "$f for x in <0,6> using color:blue and weight:2");
install_problem_grader(~~&std_problem_grader);
$showPartialCorrectAnswers = 0;
$popup1 = PopUp(
["choose","a linear function","a quadratic function","an exponential function","a power function"],
"a power function",
);
$popup2 = PopUp(
["choose","0","1","2","2.5","3","3.5","4.0"],
"$c",
);
$popup3 = PopUp(
["choose","d is less than 0", "d is between 0 and 1", "d is greater than 1"],
"d is less than 0",
);
BEGIN_PGML
Consider the function given by the following graph:
>> [@ image(insertGraph($gr), width=>$pixels, height=>$pixels, tex_size=>900,extra_html_tags=>'alt="Graph of a decreasing, concave up function in quadrant I, which passes through (1,'.$c.') " ' ) @]*
[` f(x)=c\cdot x^d `] <<
a. Which type of function is this? This is [_________]{$popup1}
b. What is the value of [` c `] ? [` c = `][____]{$popup2}
c. Choose the best option for [` d `]: [_________]{$popup3}
END_PGML
BEGIN_PGML_SOLUTION
*SOLUTION*
a. This is [@ $popup1->correct_ans() @]* .
b. [` c = [$c] `], the value of the function at 1, and
c. [@ $popup3->correct_ans() @]* , since [` c>0 `] and the power function is decreasing when [` x>0 `].
END_PGML_SOLUTION
ENDDOCUMENT();