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Mathematics
Problem
A pair of tangents are drawn from the origin to the circle
x
2
+
y
2
+
20
(
x
+
y
)
+
20
=
0
x^2 + y^2 + 20(x + y) + 20 = 0
x
2
+
y
2
+
20
(
x
+
y
)
+
20
=
0
. The equation of the pair of tangents is - (A)
x
2
+
y
2
+
5
x
y
=
0
x^2 + y^2 + 5xy = 0
x
2
+
y
2
+
5
x
y
=
0
(B)
x
2
+
y
2
+
10
x
y
=
0
x^2 + y^2 + 10xy = 0
x
2
+
y
2
+
10
x
y
=
0
(C)
2
x
2
+
2
y
2
+
5
x
y
=
0
2x^2 + 2y^2 + 5xy = 0
2
x
2
+
2
y
2
+
5
x
y
=
0
(D)
2
x
2
+
2
y
2
−
5
x
y
=
0
2x^2 + 2y^2 - 5xy = 0
2
x
2
+
2
y
2
−
5
x
y
=
0
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