document.write( "Question 1022660: Use implicit differentiation to find an equation of the tangent line to the ellipse at the given point.
\n" ); document.write( "x^2/4 + y^2/10= 14, (4, 10)
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Algebra.Com's Answer #638312 by robertb(5830)\"\" \"About 
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If \"x%5E2%2F4+%2B+y%5E2%2F10=+14\", then after differentiating implicitly and simplifying, we get\r
\n" ); document.write( "\n" ); document.write( "\"x%2F2%2B%28y%28dy%2Fdx%29%29%2F5+=+0\"\r
\n" ); document.write( "\n" ); document.write( "Substituting the coordinates of (4,10) into the last equation, we get\r
\n" ); document.write( "\n" ); document.write( "\"4%2F2%2B%2810%28dy%2Fdx%29%29%2F5+=+0\"\r
\n" ); document.write( "\n" ); document.write( "==> \"2%2B+2%28dy%2Fdx%29+=+0\", or \"dy%2Fdx+=+-1\".\r
\n" ); document.write( "\n" ); document.write( "Hence the equation of the tangent line to the ellipse at the point (4,10) is \r
\n" ); document.write( "\n" ); document.write( "y-10 = -(x-4), or \r
\n" ); document.write( "\n" ); document.write( "\"highlight%28x+%2B+y+=+14%29\"
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