A) \[x+y=2\]
B) \[x+y=2\sqrt{2}\]
C) \[x+y=4\]
D) \[x+y=8\]
Correct Answer: B
Solution :
Equation of circle is \[{{x}^{2}}+{{y}^{2}}+4x-4y+4=0\]whose centre is (-2, 2). Let the equation of required tangent be\[x+y=a\], then length of perpendicular from centre is equal to radius of circle. \[\therefore \] \[\left| \frac{-2+2-a}{\sqrt{2}} \right|=2\] \[\Rightarrow \] \[a=2\sqrt{2}\] Hence, the equation of tangent is \[x+y=2\sqrt{2}\]You need to login to perform this action.
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