Question
A triangle is formed by the tangents at the point (2, 2) on the curves and , and the line . If is the radius of its circumcircle, then is equal to ___________.
Answer: 2
Solution
This problem asks for the square of the circumradius () of a triangle formed by three specific lines. A common strategy for finding the circumradius () of a triangle is to first determine if it's a right-angled triangle. If it is, the circumradius is simply half the length of its hypotenuse. Otherwise, the general formula (where are side lengths and is the area) is used, or the circumcenter can be found. Given that the expected answer for is a simple integer, a right-angled triangle is a strong possibility, as it significantly simplifies calculations.
Let's break down the solution into clear steps.