CBSE 11TH MATHEMATICS - Online Test

Answer : Option B
Explaination / Solution:

Answer : Option D
Explaination / Solution:

N is set of natural number,so

x = 1/y

when y=1 then x=1

so

1 ∈Q

Answer : Option D
Explaination / Solution:

Answer : Option D
Explaination / Solution:

Answer : Option D
Explaination / Solution:

Answer : Option D
Explaination / Solution:

Least square lines of regression give best possible estimates when the lines coincide at that point ρ=±1

Answer : Option D
Explaination / Solution:

The equation of the pair of straight lines paasing through the origin is fiven by is given by ax2 + 2hxy + by2 =0

The condition for perpendicularity between the pair of lines is a+b = 0

Hence the locus of the pair of these perpendicular straight lines should be xy = 0

Answer : Option D
Explaination / Solution:

p∨∼p≡T

T∨p≡T

Answer : Option C
Explaination / Solution:

Because line joining the points (a, 0) and (0, b)  will be diameter and it's mid-point will be centre of the circle.

Or let the equation of circle be (x−h)2+(y−k)2=r2

as circle passes through  (0,0) , (a,0) and (0,b), they will satisfy the above equation

putting the points in above equation we get

h2+k2=r2

(a−h)2+k2=r2  ---(ii)

h2+(b−k)2=r2 ---(iii)

Solving (i) and (ii),we get  h=a2

whereas solving (i) and (iii) we get k=b2

hence its center is (a2,b2)

Answer : Option A
Explaination / Solution:

he value of cosθ$\cos \theta$  lies between - 1 and 1 

But when t=2 the value of   cosθ=1+t21−t2,t≠0$\cos \theta =\frac{1+t^2}{1-t^2},t\ne 0$ is 5−3 which is more than 1 , so it is not possible.