Equation of chord of circle
passing through
such that
,is given by
none of these
Key concept: Using the concept of parametric equation of any a line.
Any line passing through will be of the form
If this line cuts the circle
, then
.This is a quadratic equation in
, roots of this equation will represent distance PB and PA. Let the roots be
and
.
Then ,
then
So required chord will be
Alternative solution:
Key concept: Using the basic property of a circle.
From (1) and (2), we have
. Now diameter of the circle is
(as radius is
)
Hence line passes through the centre
.
Hence (B) is the correct answer.
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