ExamBro
ExamBro
JEE Mains · Maths · STD 11 - 10.1 circle and system of circle

The absolute difference between the squares of the radii of the two circles passing through the point \((-9,4)\) and touching the lines \(x+y=3\) and \(x-y=3\), is equal to ______.

  1. A 768
  2. B 767
  3. C 766
  4. D 735
Verified Solution

Answer & Solution

Correct Answer

(A) 768

Step-by-step Solution

Detailed explanation

Centre \((\mathrm{a}, 0)\) \(\mathrm{r}=\left|\frac{\mathrm{a}-0-3}{\sqrt{2}}\right|\) \(\operatorname{circle}(x-a)^2+y^2=\left(\frac{a-3}{\sqrt{2}}\right)^2\) passes through \((-9,4)\) \(2\left(a^2+18 a+81+16\right)=\left(a^2-6 a+9\right)\) \(\mathrm{a}^2+42 \mathrm{a}+185=0\)…