x^2+y^2+(√3 t+1)x+ty+t^2-2
=(x+(√3 t+1)/2)^2+(y+t/2)^2+t^2-2-t^2/4-(√3 t+1)^2/4
=(x+(√3 t+1)/2)^2+(y+t/2)^2+t^2*3/4-2-(3*t^2+2√3 t+1)/4
=(x+(√3 t+1)/2)^2+(y+t/2)^2-√3 t/2-9/4=0
√3 t/2+9/4>0,t>-3*√3 /2
圆的直径是6,半径是3,√3 t/2+9/4=9,t=27/2√3=9√3/2
x^2+y^2+(√3 t+1)x+ty+t^2-2
=(x+(√3 t+1)/2)^2+(y+t/2)^2+t^2-2-t^2/4-(√3 t+1)^2/4
=(x+(√3 t+1)/2)^2+(y+t/2)^2+t^2*3/4-2-(3*t^2+2√3 t+1)/4
=(x+(√3 t+1)/2)^2+(y+t/2)^2-√3 t/2-9/4=0
√3 t/2+9/4>0,t>-3*√3 /2
圆的直径是6,半径是3,√3 t/2+9/4=9,t=27/2√3=9√3/2