If the circle $x^{2}+y^{2}-2 g x+6 y-19 c=0, g, c \in \mathbb{R}$ passes through the point $(6,1)$ and its centre lies on the line $x-2 c y=8$, then the length of intercept made by the circle on $x$-axis is :
Solution
<p>Circle : ${x^2} + {y^2} - 2gx + 6y - 19c = 0$</p>
<p>It passes through $h(6,1)$</p>
<p>$\Rightarrow 36 + 1 - 12g + 6 - 19c = 0$</p>
<p>$= 12g + 19c = 43$ ..... (1)</p>
<p>Line $x - 2cy = 8$ passes through centre</p>
<p>$\Rightarrow g + 6c = 8$ ...... (2)</p>
<p>From (1) & (2)</p>
<p>$g = 2,\,c = 1$</p>
<p>$C:{x^2} + {y^2} - 4x + 6y - 19 = 0$</p>
<p>x intercept $= 2\sqrt {{g^2} - C}$</p>
<p>$= 2\sqrt {4 + 19}$</p>
<p>$= 2\sqrt {23}$</p>
About this question
Subject: Mathematics · Chapter: Circles · Topic: Equation of a Circle
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