document.write( "Question 1168162: the endpoints of major and minor axes of an ellipse are (1,1),(3,4),(1,7)and(-1,4).sketch the ellipse give the question in standard form and find its foci eccentricity and directrices \n" ); document.write( "
Algebra.Com's Answer #792806 by MathLover1(20849)\"\" \"About 
You can put this solution on YOUR website!
so, the endpoints of major axes are (\"1\",\"1\") and (\"1\",\"7\"), -> it’s ellipse with \"vertical\" major axis
\n" ); document.write( "distance \"2b=6+\"=>\"b=3\"\r
\n" ); document.write( "\n" ); document.write( "the endpoints of minor axes are (\"3\",\"4\") and (\"-1\",\"4\"), distance \"2a=4+\"=>\"a=2\"\r
\n" ); document.write( "\n" ); document.write( "center is midpoint of both axes, at (\"%283%2B%28-1%29%29%2F2\",\"%284%2B4%29%2F2\")=(\"1\",\"4+\")=>\"+h=1\", \"k=4\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Standard form of equation for ellipse with vertical major axis:
\n" ); document.write( "
\n" ); document.write( "\"%28x-h%29%5E2%2Fa%5E2%2B%28y-k%29%5E2%2Fb%5E2=1\", \r
\n" ); document.write( "\n" ); document.write( "if
\n" ); document.write( "\"a=2\"
\n" ); document.write( "\"b=3\"
\n" ); document.write( "\"h=1\"
\n" ); document.write( "\"k=4\"
\n" ); document.write( "then\r
\n" ); document.write( "\n" ); document.write( " \"%28x-1%29%5E2%2F4%2B%28y-4%29%5E2%2F9=1\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "sketch the ellipse \r
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "give the question in standard form and find its foci eccentricity and directrices\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Foci:
\n" ); document.write( "For an ellipse with major axis parallel to the y-axis, the foci points are defined as :
\n" ); document.write( "(\"h\",\"+k%2Bc\"),(\"h\",\"k-c\"), where \"c=sqrt%28b%5E2-a%5E2%29\" is the distance from the center (\"h\",\"k\")\r
\n" ); document.write( "\n" ); document.write( "so, since \"h=1\" and \"k=4\" we have:\r
\n" ); document.write( "\n" ); document.write( " (\"1\",\"4%2Bc\"),(\"1\",\"4-c\")\r
\n" ); document.write( "\n" ); document.write( "since \"a=2\" and \"b=3\", we have:\r
\n" ); document.write( "\n" ); document.write( "\"c=sqrt%28b%5E2-a%5E2%29=sqrt%283%5E2-2%5E2%29=sqrt%289-4%29=sqrt%285%29\"\r
\n" ); document.write( "\n" ); document.write( "then\r
\n" ); document.write( "\n" ); document.write( "(\"1\",\"4-sqrt%285%29\")≈(\"1\",1.8}}}), (\"1\",\"4%2Bsqrt%285%29\")≈(\"1%2C6.2\")\r
\n" ); document.write( "\n" ); document.write( "eccentricity is \"c%2Fb=sqrt%285%29%2F3\"\r
\n" ); document.write( "\n" ); document.write( "directrices: solve equation for \"y\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=+%281%2F2%29%288-3sqrt%28-x%5E2%2B2x%2B3%29%29\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=+%281%2F2%29%283sqrt%28-x%5E2%2B2x%2B3%29+%2B+8%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );