Important Questions for Class 12 Chapter 1 - Relation and Function

We have come up with CBSE important questions. So, you can benefit a lot by practicing the questions. The more you practice, the better marks you get in the examinations. Click on the link below and Download your free CBSE important questions class 12th mathematics.

Important questions based on NCERT syllabus for Class 12 Chapter 1 - Relation and Function:

Question 1: Find the domain and Range of the function x^2-4/x-2

Solution: Let f(x) = x^2-4/x-2

If we simplify f(x) we get x+2

Hence the domain of the function R and Range is also Range

Question 2: Given that 3x - 4 and g(x) = (x-2)/3. Determine (fog)(x) and (gof)(x)

Solution: (fog)(x) = 3g(x) - 4 = 3((x-2)/3) - 4 = x - 6

(gof)(x) = (f(x)-2)/3 = (3x - 4 - 3)/3 = 3x - 7/3

Question 3: For any function f(x) = x + 1, determine the range when the domain = {-6, -4, -2, 0, 2, 4 , 6}

Solution:

For the given values of x, we have
f(-6) = -6 + 1 = -5
f(-4) = -4 + 1 = -3
f(-2) = -2 + 1 = -1
f(0) = 0 + 1 = 1
f(2) = 2 + 1 = 3
f(4) = 4 + 1 = 5
f(6) = 6 + 1 = 7
Hence, we can write the given function as a set of ordered pairs as follows:
{(-6, -5), (-4, -3), (-2, -1), (0, 1), (2, 3), (4,5), (6,7)}
And, the range of the function = {-5, -3, -1, 1, 3, 5, 7}

Question 4: Let A = {2,3,4}. Find one to one function from A to A.

Solution: {(2,2)(2,3)(2,4)}{(3,3)(3,4)(3,2)}{4,4)(4,2)(4,3)}

{(2,2)(3,4)(4,3)}{(2,4)(3,3)(4,2)}{(2,3)(3,2)(4,4)}