document.write( "Question 798328: show that the line y=2x+3 is the equation of the tangent of the ellipse 4x^2+2y^2=2. hence find the coordinate of the point of contact \n" ); document.write( "
Algebra.Com's Answer #482153 by josgarithmetic(39628)\"\" \"About 
You can put this solution on YOUR website!
You would expect exactly one intersection point. Substitute for y and solve for x.\r
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\n" ); document.write( "\n" ); document.write( "\"4x%5E2%2B2%282x%2B3%29%5E2=2\", that substitution done,
\n" ); document.write( "\"2x%5E2%2B%282x%2B3%29%5E2=1\"
\n" ); document.write( "\"2x%5E2%2B4x%5E2%2B12x%2B9=1\"
\n" ); document.write( "\"6x%5E2%2B12x%2B8=0\"
\n" ); document.write( "\"3x%5E2%2B6x%2B4=0\"\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-6%2B-sqrt%2836-4%2A3%2A4%29%29%2F%282%2A3%29\"
\n" ); document.write( "\"x=%28-6%2B-sqrt%2836-48%29%29%2F%282%2A3%29\"
\n" ); document.write( "\"x=%28-6%2B-sqrt%28-12%29%29%2F%282%2A3%29\"
\n" ); document.write( "\"x=%28-3%2B-+i%2Asqrt%283%29%29%2F%283%29\", apparently NOT tangent! A COMPLEX solution!\r
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\n" ); document.write( "\n" ); document.write( "I've checked this over twice. You would not be expecting a complex solution, but you want instead a single real solution. One of your equations must be wrong. \r
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\n" ); document.write( "\n" ); document.write( "A better look at the graph:\r
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