please solve all question....
Answers
Let the equation of the required circle be
(x – h)^2 + (y – k)^2 = r^2.
Since the centre of the circle passes through (0, 0),
(0 – h)^2 + (0 – k)^2 = r^2
⇒ h^2 + k^2 = r^2
The equation of the circle now becomes
(x – h)^2 + (y – k)^2 = h^2 + k^2.
It is given that the circle makes intercepts a and b on the coordinate axes. This means that the circle passes through points (a, 0) and (0, b).
Therefore,
(a – h)^2 + (0 – k)^2 = h^2 + k^2 …………………… (1)
(0 – h)^2 + (b – k)^2 = h^2 + k^2 …………………… (2)
From equation (1),
we obtain a^2 – 2ah + h^2 + k^2 = h^2 + k^2
⇒ a2 – 2ah = 0
⇒ a(a – 2h) = 0
⇒ a = 0 or (a – 2h) = 0
However, a ≠ 0; hence, (a – 2h) = 0 ⇒ h =a/2.
From equation (2)
, we obtain h2 + b2 – 2bk + k^2 = h^2 + k^2
⇒ b2 – 2bk = 0
⇒ b(b – 2k) = 0
⇒ b = 0 or(b – 2k) = 0
However,
b ≠ 0; hence, (b – 2k) = 0 ⇒ k =b/2.
Thus, the equation of the required circle is
x^2+y^2-ax-by=0