11.) b and c.
Q1. If a quadrilateral formed by four tangents to the ellipse 4x2+5y2=20 is a square then:
(a) the vertices of the square lie on y=±x
(b) the vertices of the square lie on x2+y2=9
(c) the area of all such squares is a constant
(d) only two such squares are possible
PARAGRAPH
P(a,5a) and Q(4a,a) are two points. Two circles are drawn through these points touching y-axis
Q1. Centre of these circles is at
(a) (a,a) (b) (205a/18 , 29a/3) (c) (59a/2, 3a) (d) (3a , 29a/3)
Q2. Angle of intersection of these circles is
(a) tan-1(4/3) (b) tan-1(40/9) (c) tan-1(84/187) (d) none of these
Q3. If C1, C2 are the centrs of these circles then area of ΔOC1C2 where I is the origin is
(a) a2 (b) 5a2 (c) 10a2 (d) 20a2
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3 Answers
1paragraph:
take the circle:
(x-r)2 + (y-p)2 =r2
center of the circle = (r,p) and radius =r
two unknowns.
two eqns.
