If the mean deviation of the numbers 1, 1 + d, 1+ 2d, ... , 1 + 100d from their mean is 255, then the d is equal to
10.0
20.0
10.1
10.1
If the roots of the equation bx2+ cx + a = 0 be imaginary, then for all real values of x, the expression 3b2x2 + 6bcx + 2c2 is
greater than 4ab
less than 4ab
greater than -4ab
greater than -4ab
Let A and B denote the statements
A: cos α + cosβ + cosγ = 0
B : sinα + sinβ + sinγ = 0
If cos(β – γ) + cos(γ – α) + cos(α – β) = – 3/2, then
A is true and B is false
A is false and B is true
both A and B are true
both A and B are true
If A, B and C are three sets such that A ∩ B = A∩ C and A ∪ B = A ∪ C, then
A = B
A = C
B = C
B = C
The projections of a vector on the three coordinate axis are 6, - 3, 2 respectively. The direction cosines of the vector are
6, –3, 2
6/5, -3/5, 2/5
6/7, -3/7, 2/7
6/7, -3/7, 2/7
C.
6/7, -3/7, 2/7
Projection of a vector on coordinate axis are
x2-x1, y2-y1, z2-z1
x2-x1 = 6, y2-y1 = -3, z2-z1 = 2
Three distinct points A, B and C are given in the 2 – dimensional coordinate plane such that the ratio of the distance of any one of them from the point (1, 0) to the distance from the point ( - 1, 0) is equal to 1/3 . Then the circumcentre of the triangle ABC is at the point
(0,0)
(5/4, 0)
(5/2, 0)
(5/2, 0)
The ellipse x2+ 4y2= 4 is inscribed in a rectangle aligned with the coordinate axes, which in turn is inscribed in another ellipse that passes through the point (4, 0). Then the equation of the ellipse is
x2+ 16y2= 16
x2+ 12y2= 16
4x2+ 48y2= 48
4x2+ 48y2= 48
The differential equation which represents the family of curves y=c1ec2xe, where c1 and c2 are arbitrary constants, is
y' =y2
y″ = y′ y
yy″ = y′
yy″ = y′