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

If f : R → (0, 2) defined by `f (x) =(e^x - e^(x))/(e^x +e^(-x))+1`is invertible , find f^-1.

Let f : [−1, ∞) → [−1, ∞) be given by f(x) = (x + 1)² − 1, x ≥ −1. Show that f is invertible. Also, find the set S = {x : f(x) = f⁻¹ (x)}.

Let A = {x &epsis; R | −1 ≤ x ≤ 1} and let f : A → A, g : A → A be two functions defined by f(x) = x² and g(x) = sin (π x/2). Show that g⁻¹ exists but f⁻¹ does not exist. Also, find g−1.

Let f be a function from R to R, such that f(x) = cos (x + 2). Is f invertible? Justify your answer.

If A = {1, 2, 3, 4} and B = {a, b, c, d}, define any four bijections from A to B. Also give their inverse functions.

Let A and B be two sets, each with a finite number of elements. Assume that there is an injective map from A to B and that there is an injective map from B to A. Prove that there is a bijection from A to B.

If f : A → A, g : A → A are two bijections, then prove that fog is an injection ?

If f : A → A, g : A → A are two bijections, then prove that fog is a surjection ?

Which one of the following graphs represents a function?

Which of the following graphs represents a one-one function?

If A = {1, 2, 3} and B = {a, b}, write the total number of functions from A to B.

If A = {a, b, c} and B = {−2, −1, 0, 1, 2}, write the total number of one-one functions from A to B.

Write the total number of one-one functions from set A = {1, 2, 3, 4} to set B = {a, b, c}.

If f : R → R is defined by f(x) = x², write f⁻¹ (25)

If f : C → C is defined by f(x) = x², write f⁻¹ (−4). Here, C denotes the set of all complex numbers.

If f : R → R is given by f(x) = x³, write f⁻¹ (1).

Let C denote the set of all complex numbers. A function f : C → C is defined by f(x) = x³. Write f⁻¹(1).

Let f  be a function from C (set of all complex numbers) to itself given by f(x) = x³. Write f⁻¹ (−1).

If f : C → C is defined by f(x) = x⁴, write f⁻¹ (1).