document.write( "Question 1209599: The function D(x) = sin(|x|) is concave up on the interval\r
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Algebra.Com's Answer #849648 by mccravyedwin(406)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "D(x) = sin(|x|)\r\n" );
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document.write( "Concave upward means like a U. \r\n" );
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document.write( "Absolute values are always positive or zero.  So in D(x), we are always taking\r\n" );
document.write( "sines of positive or zero numbers, so D(x) will only be concave upward when the\r\n" );
document.write( "sines of positive numbers or zero are negative or zero.  This only occurs in\r\n" );
document.write( "quadrants 3 and 4. \r\n" );
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document.write( "All choices except 2.\r\n" );
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document.write( "Answer: choices 1, 3, and 4.\r\n" );
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document.write( "Edwin
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