Science (English Medium) Class 12 - CBSE Question Bank Solutions

Evaluate the following:

`cosec^-1{cosec  (-(9pi)/4)}`

Evaluate the following:

`cot^-1(cot  pi/3)`

Evaluate the following:

`cot^-1(cot  (4pi)/3)`

Evaluate the following:

`cot^-1(cot  (9pi)/4)`

Show that the relation R defined by R = {(a, b) : a – b is divisible by 3; a, b ∈ Z} is an equivalence relation.

Evaluate the following:

`cot^-1(cot  (19pi)/6)`

Evaluate the following:

`cot^-1{cot (-(8pi)/3)}`

Evaluate the following:

`cot^-1{cot  ((21pi)/4)}`

Show that the relation R on the set Z of integers, given by
R = {(a, b) : 2 divides a – b},  is an equivalence relation.

Prove that the relation R on Z defined by
(a, b) ∈ R ⇔ a − b is divisible by 5
is an equivalence relation on Z.

Let n be a fixed positive integer. Define a relation R on Z as follows:
(a, b) ∈ R ⇔ a − b is divisible by n.
Show that R is an equivalence relation on Z.

Let Z be the set of integers. Show that the relation
 R = {(a, b) : a, b ∈ Z and a + b is even}
is an equivalence relation on Z.

Write the following in the simplest form:

`cot^-1  a/sqrt(x^2-a^2),|  x  | > a`

m is said to be related to n if m and n are integers and m − n is divisible by 13. Does this define an equivalence relation?

Let R be a relation on the set A of ordered pair of integers defined by (x, y) R (u, v) if xv = yu. Show that R is an equivalence relation.

Write the following in the simplest form:

`tan^-1{x+sqrt(1+x^2)},x in R `

Show that the relation R on the set A = {x ∈ Z ; 0 ≤ x ≤ 12}, given by R = {(a, b) : a = b}, is an equivalence relation. Find the set of all elements related to 1.

Write the following in the simplest form:

`tan^-1{sqrt(1+x^2)-x},x in R`

Let L be the set of all lines in XY-plane and R be the relation in L defined as R = {L₁, L₂) : L₁ is parallel to L₂}. Show that R is an equivalence relation. Find the set of all lines related to the line y= 2x + 4.

Write the following in the simplest form:

`tan^-1{(sqrt(1+x^2)-1)/x},x !=0`