document.write( "Question 35524: sketch and find the equation
\n" ); document.write( "Foci=(2,6) and (2,-6)
\n" ); document.write( "difference in focal radii is 4\r
\n" ); document.write( "\n" ); document.write( "that is all the information that it gives me. and i have to sketch and find the equation using that information
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Algebra.Com's Answer #22604 by venugopalramana(3286)\"\" \"About 
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WE HAVE TO ASCERTAIN THE FOLLOWING FIRST
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\n" ); document.write( "Focal Radius\r
\n" ); document.write( "\n" ); document.write( "This term has distinctly different definitions for different authors.\r
\n" ); document.write( "\n" ); document.write( "Usage 1: For some authors, this refers to the distance from the center to the focus for either an ellipse or a hyperbola. This definition of focal radius is usually written c.\r
\n" ); document.write( "\n" ); document.write( "Usage 2: For other authors, focal radius refers to the distance from a point on a conic section to a focus. In this case the focal radius varies depending where the point is on the curve (unless the conic in question is a circle). If there are two foci then there are two focal radii.\r
\n" ); document.write( "\n" ); document.write( "Note: Using this second definition, the sum of the focal radii of an ellipse is a constant. It is the same as the length of the major diameter. The difference of the focal radii of a hyperbola is a constant. It is the distance between the vertices.
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\n" ); document.write( "NOW ON TO YOUR PROBLEM
\n" ); document.write( "sketch and find the equation
\n" ); document.write( "Foci=(2,6) and (2,-6)
\n" ); document.write( "difference in focal radii is 4
\n" ); document.write( "that is all the information that it gives me. and i have to sketch and find the equation using that information
\n" ); document.write( "SINCE THE DIFFERENCE IN FOCAL RADII IS GIVEN TO BE CONSTANT LET US TAKE IT AS HYPERBOLA BY THE SECOND DEFINITION.
\n" ); document.write( "IN WHICH CASE DIFFERENCE IN FOCAL RADII=2B=4...B=2
\n" ); document.write( "FOR THE STD.EQN.OF HYPERBOLA WE HAVE
\n" ); document.write( "(Y-K)^2/B^2-(X-H)^2/A^2=1....WE HAVE
\n" ); document.write( "FOCI ARE {H,K+BE} AND {H,K-BE}....H=2....K+BE=6...K-BE=-6...HENCE K=0 AND BE=6
\n" ); document.write( "SINCE B=2...E=6/2=3
\n" ); document.write( "WHERE E IS
\n" ); document.write( "ECCENTRICITY
\n" ); document.write( "=SQRT{(A^2+B^2)/B^2}=3...SQUARING
\n" ); document.write( "9=(A^2+4)/4
\n" ); document.write( "36=A^2+4
\n" ); document.write( "A^2=36-4=32
\n" ); document.write( "HENCE EQN.OF HYPERBOLA IS
\n" ); document.write( "Y^2/4- (X-2)^2/32=1
\n" ); document.write( "GRAPH IS
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