The given function of f(x) is, f(x)=x2+2hx+2c2 f(x)=(x+b)2+2c2−b2 The minimum valuc of f(x)=2c2−b2 The given function of g(x) is, g(x)=−x2−2cx+b2=−[(x+c)2−b2−c2] g(x)=−(x+c)2+b2+c2 The maximum value of g(x)=b2+c2 According to given conditions, 2c2−b2>b2+c2 c2>2b2