document.write( "Question 88883: I have a problem with a graph. Here is the link. \r
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Algebra.Com's Answer #64570 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
First lets find the center:\r
\n" ); document.write( "\n" ); document.write( "Since the ellipse stretches from x=1 to x=9, this means the horizontal center is the average of 1 and 9. So add 1 and 9 and divide by 2\r
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\n" ); document.write( "\n" ); document.write( "\"%281%2B9%29%2F2=10%2F2=5\"\r
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\n" ); document.write( "\n" ); document.write( "So the horizontal center is \"x=5\"\r
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\n" ); document.write( "\n" ); document.write( "Since the ellipse stretches from y=1 to x=7, this means the vertical center is the average of 1 and 7. So add 1 and 7 and divide by 2\r
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\n" ); document.write( "\n" ); document.write( "\"%281%2B7%29%2F2=8%2F2=4\"\r
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\n" ); document.write( "\n" ); document.write( "So the vertical center is \"y=4\"\r
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\n" ); document.write( "\n" ); document.write( "So the center of the ellipse is (5,4)\r
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\n" ); document.write( "\n" ); document.write( "Now lets find the radii:\r
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\n" ); document.write( "\n" ); document.write( "Now we can find the horizontal radius by subtracting 5 from 9 (this will find the distance from the horizontal center to either the left or right edge)\r
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\n" ); document.write( "\n" ); document.write( "\"9-5=4\" \r
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\n" ); document.write( "\n" ); document.write( "So the horizontal radius is 4 (ie it is 4 units from the center to the edge if you use the x-axis)\r
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\n" ); document.write( "\n" ); document.write( "We can find the vertical radius by subtracting 4 from 7 (this will find the distance from the vertical center to either the top or bottom edge)\r
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\n" ); document.write( "\n" ); document.write( "\"7-4=3\" \r
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\n" ); document.write( "\n" ); document.write( "So the vertical radius is 3 (ie it is 3 units from the center to the edge if you use the y-axis)\r
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\n" ); document.write( "\n" ); document.write( "Now using the general equation of the ellipse \r
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\n" ); document.write( "\n" ); document.write( "\"%28x-h%29%5E2%2Fa%5E2%2B%28y-k%29%5E2%2Fb%5E2=1\" where (h,k) is the center, a is the horizontal radius, and b is the vertical radius\r
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\n" ); document.write( "\n" ); document.write( "\"%28x-5%29%5E2%2F4%5E2%2B%28y-4%29%5E2%2F3%5E2=1\" Plug in \"h=5\", \"k=4\", \"a=4\" and \"b=3\" (these were solved for earlier)\r
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\n" ); document.write( "\n" ); document.write( "\"%28x-5%29%5E2%2F16%2B%28y-4%29%5E2%2F9=1\" Square each value\r
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\n" ); document.write( "\n" ); document.write( "Notice if we graph the equation (you need to solve for y first) we get\r
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\n" ); document.write( "\n" ); document.write( "and this shows that our answer is correct.\r
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\n" ); document.write( "\n" ); document.write( "So the answer is B)
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