The point diametrically opposite to the point
P (1, 0) on the circle x2+y2+2x+4y−3=0, is
(-3,-4)
(3, 4)
(3, -4)
(-3, 4)
The coordinate of the centre of the circle are
(-1,-2). Let Q (a, b) be diametrically opposite to P. Then,
mid-point of PQ is the centre of the circle.
∴ a+12=−1 and b+02=−2⇒a=−3 and b=−4
Hence, required point is (- 3, - 4).