PSIN(θ+π/4)=P(SINθ*COSπ/4+COSθ*SINπ/4)=√2/2*PSINθ+√2/2*PCOSθ=√2/2(X+Y)=2=> X+Y=2√2 =>X+Y-2√2=0P=4 => P²=16 => X²+Y²=16 圆心(0,0),半径R=4.圆心到直线距离:D=|-2√2|/√(1+1)=2...