document.write( "Question 1026719: The equation x^2+y^2-2x-4y-4=0 represents a circle. What are the coordinates for the center of the circle? What is the length of the radius of the circle? \n" ); document.write( "
Algebra.Com's Answer #641988 by mathmate(429)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Question: \n" ); document.write( "The equation x^2+y^2-2x-4y-4=0 represents a circle. What are the coordinates for the center of the circle? What is the length of the radius of the circle? \n" ); document.write( " \n" ); document.write( "Solution: \n" ); document.write( "The general equation of a circle centred at (a,b) with radius r is written as: \n" ); document.write( " \n" ); document.write( "By completing squares, we have \n" ); document.write( " \n" ); document.write( "= \n" ); document.write( "= \n" ); document.write( "= \n" ); document.write( "=0 \n" ); document.write( "Hence the equation of the circle can be rewritten as \n" ); document.write( "(x-1)^2+(y-2)^2=3^3 \n" ); document.write( "By comparison with the general equation (1) above, we conclude that the centre of the circle is (a,b)=(1,2) and the radius is 3. \n" ); document.write( " \n" ); document.write( " |