JEE Main 2022 · 25 July · Evening Shift · Mathematics · Circle
If the circles x ^ 2 + y ^ 2 + 6x + 8y + 16 = 0 and x ^ 2 + y ^ 2 +...
If the circles x2+y2+6x+8y+16=0 and x2+y2+2(3−3)x+2(4−6)y=k+63+86, k>0, touch internally at the point P(α,β), then (α+3)2+(β+6)2 is equal to _______.
Correct answer
0
Step-by-step solution
The circle x2+y2+6x+8y+16=0 has centre \left(- 3, - 4\right)andradius\sqrt{9 + 16 - 16} = 3units.</p><p>Thecircle{x}^{2} + {y}^{2} + 2\left(3 - \sqrt{3}\right)x + 2(4−6)y=k+63+86,k>0 has centre \left(\sqrt{3} - 3, \sqrt{6} - 4\right)andradius\sqrt{{\left(\sqrt{3} - 3\right)}^{2} + {\left(\sqrt{6} - 4\right)}^{2} + k + 6\sqrt{3} + 8\sqrt{6}} = \sqrt{k + 34}</p><p>Giventhatthesetwocirclestouchinternally,so</p><p>distancebetweentheircentres= \left|\text{differenceofradii}\right|</p><p>\sqrt{3 + 6} = \left|\sqrt{k + 34} - 3\right|
⇒k+34−3=±3
Here, k=2is only possible value \left(∵ k > 0\right)