document.write( "Question 865985: Question: Find all angles theta (I don't have a symbol for that) in radians on the interval [0,4pi] such that cos(theta) = 1/2.\r
\n" ); document.write( "\n" ); document.write( "I think I have to set a up graph from 0 to 4pi and draw a wavy line and determine at what points x crosses y=1/2. It that correct? How do I do that?
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Algebra.Com's Answer #522017 by rothauserc(4718)\"\" \"About 
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\"+graph%28+300%2C+200%2C+0%2C+13%2C+-1%2C+1%2C+cos%28x%29+%29+\"
\n" ); document.write( "note that pi = 180 degrees, therefore the interval in degrees is [0, 720]
\n" ); document.write( "the cosine of 60 degrees is 1/2
\n" ); document.write( "we convert degrees to radians = degrees * pi/180
\n" ); document.write( "60 degrees = pi/3 radians
\n" ); document.write( "from the graph, we see the following
\n" ); document.write( "the angles theta in radians are pi/3, 5*pi/3, 7*pi/3, 11*pi/3\r
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