document.write( "Question 912089: Using the expression cos (75 degrees) cos (30 degrees) + sin (75 degrees) sin (30 degrees) \r
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Algebra.Com's Answer #553554 by Edwin McCravy(20060) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "cos(75°)cos(30°)+sin(75°)sin(30°) \r\n" );
document.write( "(a)\r\n" );
document.write( "Use the double angle identity:\r\n" );
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document.write( "Observe that the given expression is the right side of this\r\n" );
document.write( "identity with  and , Substituting\r\n" );
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document.write( "Answer:  cos(45°)\r\n" );
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document.write( "(b) \r\n" );
document.write( "Since the exact vaule of cos(45°) is ,\r\n" );
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document.write( " cos(75°)cos(30°)+sin(75°)sin(30°) = \r\n" );
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document.write( "Edwin

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