Y²=4x-x²-4+4 y²=4-(x-2)² (x-2)²=4-y² x-2=√(4-y²) x=(√(4-y²))+2 y=x-x²+1/4-1/4 y=1/4-(x-1/2)² (x-1/2)²=1/4-y x-1/2=√(1/4-y) x=(√(1/4-y))+1/2