Answer:
1) A
2) D
Step-by-step explanation:
1) The equation of a circle is (x-h)²+(y-k)²=r² where (h,k) is the center and "r" is the radius of the circle. With a center of (a,-b) the equation of the circle is (x-a)²+(y+b)²=r² making A the correct answer.
2) Convert from general form into standard form:
Given: x²+y²-4x-2y+4=1
Rearrange: x²-4x+4+y²-2y=1
Set right side equal to 0: x²-4x+4+y²-2y-1=0
Complete the square: x²-4x+4+y²-2y-1+2=0+2
Evaluate: x²-4x+4+y²-2y+1=2
Condense: (x-2)²+(y-1)²=2
Therefore, the center of the circle is D) (2,1)
