Consider the family of circles `x^(2)+y^(2)-2x-2ay-8=0` passing through two fixed points A and B . Also, `S=0` is a cricle of this family, the tangent to which at A and B intersect on the line `x+2y+5=0`. If the circle `x^(2)+y^(2)-10x+2y=c=0` is orthogonal to `S=0`, then the value of c isA. 8B. 9C. 10D. 12

Consider the family of circles `x^(2)+y^(2)-2x-2ay-8=0` passing throug

1.	Consider the family of circles `x^(2)+y^(2)-2x-2ay-8=0` passing through two fixed points A and B . Also, `S=0` is a cricle of this family, the tangent to which at A and B intersect on the line `x+2y+5=0`. If the circle `x^(2)+y^(2)-10x+2y=c=0` is orthogonal to `S=0`, then the value of c isA. 8B. 9C. 10D. 12
Answer» Correct Answer - 4 Circle `x^(2)+y^(2)-10x+2y+c=0` is orthogonal to `x^(2)+y^(2)-2x-6y-8=0`. So, by applying condition of orthogonal intersection, we get `2(-5)(-1)+2(1) (-3)= c-8` `:. C= 12`

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