## DESCRIPTION
## Precalculus: Trigonometric Identities
## ENDDESCRIPTION

## KEYWORDS('trigonometry','half-angle')
## Tagged by cmd6a 5/11/06

## DBsubject('Precalculus')
## DBchapter('Analytic Trigonometry')
## DBsection('Double- and Half-Angle/Product-Sum Formulas')
## Date('')
## Author('')
## Institution('Rochester')
## TitleText1('')
## EditionText1('')
## AuthorText1('')
## Section1('')
## Problem1('')

DOCUMENT();        # This should be the first executable line in the problem.

loadMacros(
"PG.pl",
"PGbasicmacros.pl",
"PGchoicemacros.pl",
"PGanswermacros.pl",
"PGauxiliaryFunctions.pl",
"PGgraphmacros.pl",
"PGasu.pl"
);

TEXT(beginproblem());

$showPartialCorrectAnswers = 1;


$a=random(2,8,1);


#evaluate answers


$ans1=1/2;
$ans2=1/2;
$ans3=2*$a;

TEXT(EV2(<<EOT));
Use a half angle formula to fill in the blanks in the identity below:

$BR
\( (\cos($a x))^2 \) =
\{ans_rule(5) \}+\{ans_rule(5) \} \( \cos( \) \{ans_rule(5) \} \( x ) \)
EOT

ANS(num_cmp($ans1));
ANS(num_cmp($ans2));
ANS(num_cmp($ans3));


ENDDOCUMENT();        # This should be the last executable line in the problem.