+501 In terms of $\pi$, what is the area of the circle defined by the equation $2x^2+2y^2+10x-6y-18=0$?
+36916 This is the equation of a circle ......re write in standard form by 'completing the square' for x and y :
2 x^2 + 10x + 2y^2 -6y - 18 = 0 divide through by 2
x^2 + 5x + y^2 -3y = 9 complete the squares
(x+2.5)^2 + ( y-1.5)^2 = 9 + 6.25 + 2.25 <======== this equals radius ^2
17.5 = r^2 area of circle = pi r^2 area = 17.5 pi units2
+36916 This is the equation of a circle ......re write in standard form by 'completing the square' for x and y :
2 x^2 + 10x + 2y^2 -6y - 18 = 0 divide through by 2
x^2 + 5x + y^2 -3y = 9 complete the squares
(x+2.5)^2 + ( y-1.5)^2 = 9 + 6.25 + 2.25 <======== this equals radius ^2
17.5 = r^2 area of circle = pi r^2 area = 17.5 pi units2
