Answers are a list of points

Answers are lists of points

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Complete Code

Download file: PointAnswers.pg

POD for Macro Files

PG problem file

Explanation

DOCUMENT();

loadMacros('PGstandard.pl', 'PGML.pl', 'contextLimitedPoint.pl', 'PGcourse.pl');

Preamble

Load contextLimitedPoint.pl to prevent operations between points.

Context('LimitedPoint');

$f = Compute("x^2 - 1");

$xint = List(Point("(1, 0)"), Point("(-1, 0)"));
$yint = List(Point("(0, -1)"));

Setup

Context('Point') could be used instead, which would allow mathematical operations between points (such as adding points as if they were vectors). The x-intercepts are clearly a list of points. A list with only one element is used for the y-intercepts so that a student who mistakenly enters two points will be told their second point is incorrect. If a list is not used for the y-intercepts, a student who enters two points would be given an error message instead.

BEGIN_PGML
Enter the [`x`]-intercept(s) and [`y`]-intercept(s) of [`y = [$f]`].  Enter a
point as [`(a,b)`], including the parentheses.  If there is more than one
correct answer, enter a comma separated list of points.

+ [`x`]-intercept(s): [_]{$xint}{15}

+ [`y`]-intercept(s): [_]{$yint}{15}
END_PGML

Statement

Be sure to tell students the proper syntax for how to enter their answers.

BEGIN_PGML_SOLUTION
Solution explanation goes here.
END_PGML_SOLUTION

ENDDOCUMENT();

Solution

A solution should be provided here.