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If the two circles (x-1)^2+(y-3)^2=r^2and x^2+y^2-8 x+2 y+8=0 intersect in two distinct points, then

Option: 1

2<r<8


Option: 2

r<2


Option: 3

r=2


Option: 4

r>2


Answers (1)

best_answer

Centres of the given circles are C_1(1,3) and C_2(4,-1), and their radii, r_1=r and r_2=3.

We know that the two circles touch,

externally if   \quad C_1 C_2=r_1+r_2, and internally if   \quad C_1 C_2=\left|r_1-r_2\right|.

Thus the two circles will cut at two distinct points if

                     C_1 C_2>\left|r_1-r_2\right| \text { and } C_1 C_2<r_1+r_2\text {, i.e., if }\left|r_1-r_2\right|<C_1 C_2<r_1+r_2 \text {, }

or if  r-3<5<r+3 or if r<8 and r>2 or if , which is given in (A).

\therefore \quad (a)

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Gunjita

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