Tangents are drawn from point (-1,-4) to circle x^2 + y^2 - 2x + 4y + 1 = 0 . Length of correspondin

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10-1.Circle and System of Circles

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Tangents are drawn from the point $(-1,-4)$ to the circle $x^2 + y^2 - 2x + 4y + 1 = 0$. Length of corresponding chord of contact will be-

A

$\sqrt 2$ units

B

$2\sqrt 2$ units

C

$3\sqrt 2$ units

D

$2$ units

Solution

$R = \sqrt {1+4-1} = 2$
$(-1,-4)$ lies on director's circle of given circle
$\therefore$ $L_coc =\sqrt {4 \times 4} = 2\sqrt 2$

Standard 11

Mathematics

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