配方:
[x-(t+3)]²+[y+(1-4t²)]²=(t+3)²+(1-4t²)²-16t^4-9
[x-(t+3)]²+[y+(1-4t²)]²=-7t²+6t+1=-(7t+1)(t-1)
因为半径为正,所以有-(7t+1)(t-1)>0,得:-1/7
配方:
[x-(t+3)]²+[y+(1-4t²)]²=(t+3)²+(1-4t²)²-16t^4-9
[x-(t+3)]²+[y+(1-4t²)]²=-7t²+6t+1=-(7t+1)(t-1)
因为半径为正,所以有-(7t+1)(t-1)>0,得:-1/7