1
WB JEE 2010
+1
-0.25

If the line ax + by + c = 0 is a tangent to the curve xy = 4, then

A
a < 0, b > 0
B
a $$\le$$ 0, b > 0
C
a < 0, b < 0
D
a $$\le$$ 0, b < 0
2
WB JEE 2010
+1
-0.25

S and T are the foci of an ellipse and B is an end point of the minor axis. If STB is an equilateral triangle, the eccentricity of the ellipse is

A
$${1 \over 4}$$
B
$${1 \over 3}$$
C
$${1 \over 2}$$
D
$${2 \over 3}$$
3
WB JEE 2010
+1
-0.25

For different values of $$\alpha$$, the locus of the point of intersection of the two straight lines $$\sqrt 3 x - y - 4\sqrt 3 \alpha = 0$$ and $$\sqrt 3 \alpha x + \alpha y - 4\sqrt 3 = 0$$ is

A
a hyperbola with eccentricity 2
B
an ellipse with eccentricity $$\sqrt {{2 \over 3}}$$
C
a hyperbola with eccentricity $$\sqrt {{{19} \over {16}}}$$
D
$${3 \over 4}$$
4
WB JEE 2011
+1
-0.25

The eccentricity of the hyperbola $$4{x^2} - 9{y^2} = 36$$ is

A
$${{\sqrt {11} } \over 3}$$
B
$${{\sqrt {15} } \over 3}$$
C
$${{\sqrt {13} } \over 3}$$
D
$${{\sqrt {14} } \over 3}$$
WB JEE Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
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