Q.

A square is inscribed in the circle x2+y210x6y+30=0. One side of this square is parallel to y = x + 3. If (xi, yi) are the vertices of the square, then (xi2, yi2) is equal to          [2024]

1 160  
2 152  
3 156  
4 148  

Ans.

(2)

One side of square is y = x + k

Distance of (5, 3) to the line y = x + k is

|3  5  k|2 = 2

    |2  k| = 2      k = 0  or  k = 4

So lines are y = x and y = x – 4

Now, solving these lines with circle

y = x and x2 + y2  10x  6y + 30 = 0

    2x2  16x + 30 = 0

    x = 3, y = 3 and x = 5, y = 5

and y = x – 4 and x2 + y2  10x  6y + 30 = 0

    x = 5, y = 1 and x = 7, y = 3

i = 14 xi2 + yi2 = 9 + 9 + 25 + 25 + 25 + 1 + 49 + 9 = 152.