document.write( "Question 1085741: C AND D ARE SETS OF REAL NUMBERS\r
\n" ); document.write( "\n" ); document.write( "C{x|x<3}
\n" ); document.write( "D{x|x< has a line under 9}\r
\n" ); document.write( "\n" ); document.write( "C U D =
\n" ); document.write( "C DOWNWARD U D =\r
\n" ); document.write( "\n" ); document.write( "UNION AND INTERSECTION INTERVALS
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Algebra.Com's Answer #699827 by math_helper(2461) $\"\"$ $\"About$

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C is the set of real x such that $\"+x+%3C+3+\"$
\n" ); document.write( "That's everything to the left of the 3 below, excluding the 3 itself:
\n" ); document.write( " $\"+%0D%0A+number_line%28+600%2C+-10%2C+10%2C++3%29%0D%0A\"$
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\n" ); document.write( "\n" ); document.write( "D is the set of real x such that $\"+x+%3C=+9+\"$
\n" ); document.write( "That's everything to the left of the 9 below, including the 9 itself:
\n" ); document.write( " $\"%0D%0A+number_line%28+600%2C+-10%2C++10%2C++9%29%0D%0A%0D%0A\"$ \r
\n" ); document.write( "\n" ); document.write( "{C} U {D} is the region to the left of the 9, including the 9 itself. Since D includes C, the union of the two sets coincides with D. Using interval notation, it would be written ( $\"+-infinity+\"$ , $\"+9+\"$ ] (open paren's means that endpoint is excluded, square bracket means that endpoint is included).\r
\n" ); document.write( "\n" ); document.write( "{C} intersect {D} is the region to the left of 3 (excluding the 3 itself) and coincides with set C. In interval notation: ( $\"-infinity+\"$ , $\"+3+\"$ )\r
\n" ); document.write( "\n" ); document.write( "ЧЧ\r
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