document.write( "Question 1084215: In the (x,y) coordinate plane, which of the following is an equation of the circle having the points (3,-3) and (-5,5) as endpoints of a diamteter?
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document.write( "F) (x+1)^2 + (y-1)^2 = sqrt 32 G) (x+1)^2 + (y+1)^2 = sqrt 32 H) (x-1)^2 + (y+1)^2 = sqrt 32
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document.write( "J) (x-1)^2 + (y+1)^2 = 32 K) (x+1)^2 + (y-1)^2 = 32 \n" );
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Algebra.Com's Answer #698286 by Boreal(15235) You can put this solution on YOUR website! Need to know the center and the radius. \n" ); document.write( "Midpoint of diameter is center, which is midpoint formula, which gives (-1, 1) and the radius is the distance from the center to either end of the diameter. That is the distance formula, sqrt ((x2-x1)^2+(y2-y1)^2)= sqrt (16+16)=sqrt (32) \n" ); document.write( "so r^2=32. The equation of a circle is x^2+y^2=r^2. So once one has the sqrt of the radius (here sqrt (32)), it has to be squared (32) to be part of the equation. \n" ); document.write( "(x+1)^2+(y-1)^2=32 \n" ); document.write( "K. \n" ); document.write( " |