The conic equation in the first problem of large conic curve is generally solved by geometric method.

The coordinates of intersection points are often assumed in conic curves, and then Vieta's theorem is applied to eliminate them, that is, the intersection points are on conic curves and straight lines at the same time.

Existential problems are usually assumed to exist first and then calculated. If the result can be calculated, the hypothesis holds. If the deduction is contradictory, the assumption is not valid. Often-established problems are usually transformed into maximum problems. Put the letters aside, but pay attention to the unequal directions.