Resposta
$d = \frac{|Ax_0 + By_0 + C|}{\sqrt{A^2 + B^2}}$.
Explicação
This formula is derived from vector projection and is a standard tool in CSAT geometry problems involving tangent lines to circles.
Início / Biblioteca / CSAT (Suneung) essentials: original practice / Flashcard sintético
What is the formula for the distance $d$ from a point $(x_0, y_0)$ to the line $Ax + By + C = 0$?
Flashcard de estudo do deck CSAT (Suneung) essentials: original practice.