The center of a circle is at (4, -1) and it has a radius of 6. What is the equation of the circle?
The standard form of the equation of a circle is :
#(x - a )^2 + (y - b )^2 = r^2 #
where (a , b ) is the coords of the centre and r , the radius.
here (a , b ) = (4 , -1 ) and r = 6
substitute these values into the standard equation
#rArr (x - 4 )^2 + (y + 1 )^2 = 36 " is the equation "#