Commerce (English Medium) Class 12 - CBSE Question Bank Solutions for Mathematics

Let f : R → R, g : R → R be two functions defined by f(x) = x² + x + 1 and g(x) = 1 − x². Write fog (−2).

Let f : R → R be defined as  `f (x) = (2x - 3)/4.` write fo f^-1 (1) .

Let f be an invertible real function. Write ( f^-1  of ) (1) + ( f^-1  of ) (2) +..... +( f^-1 of ) (100 )

Let A = {1, 2, 3, 4} and B = {a, b} be two sets. Write the total number of onto functions from A to B.

Write the domain of the real function

`f (x) = sqrtx - [x] .`

Write the domain of the real function

`f (x) = sqrt([x] - x) .`

Write the domain of the real function

`f (x) = 1/(sqrt([x] - x)`.

Write whether f : R → R, given by `f(x) = x + sqrtx^2` is one-one, many-one, onto or into.

If f(x) = x + 7 and g(x) = x − 7, x ∈ R, write fog (7).

What is the range of the function

`f (x) = ([x - 1])/(x -1) ?`

If f : R → R be defined by f(x) = (3 − x³)1/3, then find fof (x).

If f : R → R is defined by f(x) = 3x + 2, find f (f (x)).

Let A = {1, 2, 3}, B = {4, 5, 6, 7} and let f = {(1, 4), (2, 5), (3, 6)} be a function from A to B. State whether f is one-one or not.

If f : {5, 6} → {2, 3} and g : {2, 3} → {5, 6} are given by f = {(5, 2), (6, 3)} and g = {(2, 5), (3, 6)}, then find fog.    [NCERT EXEMPLAR]

Let f : R → R be the function defined by f(x) = 4x − 3 for all x ∈ R Then write f .   [NCERT EXEMPLAR]

Which one the following relations on A = {1, 2, 3} is a function?
f = {(1, 3), (2, 3), (3, 2)}, g = {(1, 2), (1, 3), (3, 1)}                                                                                                        [NCERT EXEMPLAR]

Write the domain of the real function f defined by f(x) = `sqrt (25 -x^2)`   [NCERT EXEMPLAR]

Let A = {a, b, c, d} and f : A → A be given by f = {( a,b ),( b , d ),( c , a ) , ( d , c )} write `f^-1`. [NCERT EXEMPLAR]

Let f, g : R → R be defined by f(x) = 2x + l and g(x) = x²−2 for all x

∈ R, respectively. Then, find gof.  [NCERT EXEMPLAR]

If the mapping f : {1, 3, 4} → {1, 2, 5} and g : {1, 2, 5} → {1, 3}, given by f = {(1, 2), (3, 5), (4, 1)} and g = {(2, 3), (5, 1), (1, 3)}, then write fog. [NCERT EXEMPLAR]