Example 4. The positional relationship between the line $y=k x+1$ and the circle $x^{2}+y^{2}=\sqrt{2}$ is
(A) Separate:
(L) Tangent;
(C) Intersect;
(D) Determined by the value of $k$.
If we consider using the discriminant method, it would be quite troublesome. Considering the intercepts of the line and the circle on the $y$-axis are 1 and $\sqrt[4]{2}$ respectively, and $\sqrt[4]{2}>1$, we can quickly determine that the answer is $(C)$.