iran-konkur 2019 Q133

iran-konkur · Other · konkur-riazi_1398_specialized_new-curriculum Circles Chord Length and Chord Properties
133- The common chord of circle $C$ with equation $x^2 + y^2 - 4x + y^2 = 6$ is tangent to the first region of circle $C$. If the point $(-1, 4)$ lies on it, the equation of the common chord is which of the following?
(1) $x^2 + y^2 - y + 3x = 6$ (2) $x^2 + y^2 + 3y - x = 6$
(3) $x^2 + y^2 - 2y + x = 6$ (4) $x^2 + y^2 - 3y - x = 6$
\textbf{133-} The common chord of circle $C$ with equation $x^2 + y^2 - 4x + y^2 = 6$ is tangent to the first region of circle $C$. If the point $(-1, 4)$ lies on it, the equation of the common chord is which of the following?

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(1) $x^2 + y^2 - y + 3x = 6$ \hfill (2) $x^2 + y^2 + 3y - x = 6$

(3) $x^2 + y^2 - 2y + x = 6$ \hfill (4) $x^2 + y^2 - 3y - x = 6$

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