Trigonometric Identities

Trigonometric identities

Complete Code

PG problem file

Explanation

DOCUMENT();

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

Preamble

These standard macros need to be loaded.

$ans = Compute('sin(x)')->cmp(
    checker => sub {
        my ($correct, $student, $ansHash) = @_;
        my $stu_ans = $student->reduce;
        Value->Error('There is a simpler answer')
            if $stu_ans->string eq 'cos(x)*tan(x)';
        return $student == $correct;
    }
);

Setup

To prevent the student from just entering the given expression, we create a custom answer checker, which 1) performs a ->reduce which will do some small simplification, 2) returns an error if the original expression was put in and 3) then checks if the answer is correct.

An alternative method to doing this is in Proving Identities.

BEGIN_PGML
Simplify the expression as much as possible.

[`\tan(x) \cos(x) =`] [_]{$ans}{15}
END_PGML

Statement

This is the problem statement in PGML.

BEGIN_PGML_SOLUTION
Solution explanation goes here.
END_PGML_SOLUTION

COMMENT(
    'Prevents students from entering trivial identities (entering what they '
        . 'were given)');

ENDDOCUMENT();

Solution

A solution should be provided here.