LinearApprox1

Linear Approximation With Answer Hints

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This PG code shows how to ask a linear approximation question in which the answer is an equation and students receive customized answer hints.

• File location in OPL: FortLewis/Authoring/Templates/DiffCalc/LinearApprox1.pg

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PG problem file	Explanation
Problem tagging data	Problem tagging:
DOCUMENT(); loadMacros( "PGstandard.pl", "MathObjects.pl", "AnswerFormatHelp.pl", "answerHints.pl", "parserAssignment.pl", ); TEXT(beginproblem());	Initialization: We load parserAssignment.pl to require students to enter their answer as an equation of the form y=.... We load answerHints.pl to provide customized answer hints, particularly for those students who enter the slope of the line instead of the equation of the line.
Context("Numeric")->variables->add(y=>"Real"); parser::Assignment->Allow; $a = random(2,5,1); $aa = $a**2; $a2 = 2 * $a; $f = Compute("sqrt(x)"); $answer = Compute("y = $a + (1/$a2) * (x-$aa)");	Setup: We have to tell the context that we are allowing the assignment of a variable to a formula.
Context()->texStrings; BEGIN_TEXT Find the linear approximation to \( f(x) = $f \) at \( x = $aa \). Your answer should be an equation in the variables \( x \) and \( y \). $BR $BR \{ ans_rule(20) \} \{ AnswerFormatHelp("equations") \} END_TEXT Context()->normalStrings;	Main Text:
$showPartialCorrectAnswers = 1; ANS( $answer->cmp() ->withPostFilter(AnswerHints( [Formula("1/$a2"),Formula("y=1/$a2")] => ["Your answer should be an equation for a non-horizontal line.", replaceMessage=>1], )) );	Answer Evaluation: We use answer hints to remind students to enter an equation for a line, not just the slope of the line.
Context()->texStrings; BEGIN_SOLUTION Solution explanation goes here. END_SOLUTION Context()->normalStrings; COMMENT("MathObject version."); ENDDOCUMENT();	Solution:

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