On the equation of line and circle Given that a = {(x, y) | X-Y + 2 = 0}, B = {(x, y) | (x-t) ^ 2 + (Y-1) ^ 2 = 2}, and a intersection B is not equal to an empty set, then the value range of T is

On the equation of line and circle Given that a = {(x, y) | X-Y + 2 = 0}, B = {(x, y) | (x-t) ^ 2 + (Y-1) ^ 2 = 2}, and a intersection B is not equal to an empty set, then the value range of T is

A intersection B is not equal to an empty set, that is, tangent or intersection
Then the distance from the center of the circle to the straight line is less than or equal to the radius
|t-1+2|/√2