document.write( "Question 254156: How do you solve cos(45degrees + 30degrees) using trigonomic identities? \n" ); document.write( "

Algebra.Com's Answer #186447 by drk(1908) $\"\"$ $\"About$

You can put this solution on YOUR website!
The question was:
\n" ); document.write( "(i) $\"cos%2845+%2B+30%29\"$
\n" ); document.write( "We have the following identity:
\n" ); document.write( " $\"cos%28A%2BB%29+=+cosAcosB+-+sinA+sinB\"$
\n" ); document.write( "So, (i) becomes
\n" ); document.write( "(ii) $\"cos%2845+%2B+30%29+=+cos45cos30+-+sin45+sin30\"$
\n" ); document.write( "or
\n" ); document.write( "

\n" ); document.write( "which is
\n" ); document.write( " $\"cos%2845+%2B+30%29+=+%28sqrt%286%29+-+sqrt%282%29%29%2F4\"$ \n" ); document.write( "

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