document.write( "Question 206433: State the domain: g(x)= 2x+1 over x-7 \n" ); document.write( "
Algebra.Com's Answer #155992 by mickclns(59)\"\" \"About 
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A graph of \"+%282x%2B1%29+%2F+%28x-7%29+\" is \"+graph%28400%2C200%2C-70%2C25%2C-17%2C20%2C++%282x%2B1%29+%2F+%28x-7%29+%29+\"\r
\n" ); document.write( "\n" ); document.write( "As x gets larger and larger positively or negatively, y will exist (so x will also) and will get close to 2. However, as x gets closer and closer to 7 the numerator gets closer and closer to 15, but the denominator gets closer and closer to 0, meaning the denominator is tinier and tinier. But, if you take a number near 15 and divide by a tiny number you get a large (+ or -) number. For instance, if x = 6.99 then the numerator is 14.98 and the denominator is -0.01 which is the same as -1/100.
\n" ); document.write( "So, \"+g%286.99%29+=+14.98%2F-0.01+=+14.98%2A-100+=-1498+\" which is a huge number, way off the bottom of the graph and \"+g%287.01%29+=+15.02%2F0.01+=+15.02%2A100+=1502\" which is a huge number, way off the top of the graph.\r
\n" ); document.write( "\n" ); document.write( "Speaking of the graph, near to x = 7, you can see part of the graph that is a vertical line. That shouldn't actually be there. Near to 7 the actual graph just continues farther and farther off the bottom and top of the picture with nothing in the middle (in the picture, where x very near to 7). If x = 7 then g(7) is 15 / 0, but, since you can't divide by 0, g(7) does not exist, so 7 is not in the domain of g. All this is to say that the domain of g is ALL REAL NUMBERS EXCEPT FOR 7.
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