x²+(y-1)²=1令x=cosa则(y-1)²=1-cos²a=sin²ay-1=sinay=sina+1所以x+y=sina+cosa+1=√2(sina*√2/2+cosa*√2/2)+1=√2(sinacosπ/4+cosasinπ/4)+1=√2sin(a+π/4)+1所以x0+y0最小值=-√2+1...