圆：( x + a )^2 + ( y – a )^2 = 4a可得C:（ -a ,a ）由点到切线距离为半径长可得｜m - 2a｜/ 根2 = 2√2平方得 ( m - 2a )^2 = 8a所以m = 2a - 2√(2a) 或m = 2a + 2√(2a)设√a = t,t∈(0 ,2)所以m = 2t^2 - 2√...