CBSE Class 12 Sample Paper for 2025 Boards
Question 2
Question 3
Question 4
Question 5 Important
Question 6
Question 7
Question 8 Important
Question 9 Important
Question 10 Important
Question 11
Question 12 Important
Question 13 Important
Question 14
Question 15 Important
Question 16 Important
Question 17
Question 18
Question 19 [Assertion Reasoning] Important
Question 20 [Assertion Reasoning] Important You are here
Question 21 Important
Question 22
Question 23 (A)
Question 23 (B)
Question 24 (A)
Question 24 (B) Important
Question 25 Important
Question 26 Important
Question 27 Important
Question 28 (A)
Question 28 (B)
Question 29 (A) Important
Question 29 (B)
Question 30 Important
Question 31 (A) Important
Question 31 (B)
Question 32 Important
Question 33 Important
Question 34 (A)
Question 34 (B)
Question 35 (A)
Question 35 (B) Important
Question 36 (i) [Case Based]
Question 36 (ii)
Question 36 (iii) (A) Important
Question 36 (iii) (B) Important
Question 37 (i) [Case Based]
Question 37 (ii) Important
Question 37 (iii) (A) Important
Question 37 (iii) (B)
Question 38 (i) [Case Based] Important
Question 38 (ii) Important
CBSE Class 12 Sample Paper for 2025 Boards
Last updated at Sept. 26, 2024 by Teachoo
Question 20 Statement A Assertion (A): The function 𝑓:𝑅−{(2𝑛+1)𝜋/2:𝑛∈𝑍}→(−∞,−1]∪[1,∞) defined by 𝑓(𝑥)=sec 𝑥 is not one-one function in its domain. Statement R Reason (R): The line 𝑦=2 meets the graph of the function at more than one point. (A) Both (A) and (R) are true and (R) is the correct explanation of (A). (B) Both (A) and ( 𝑅 ) are true but (𝑅) is not the correct explanation of (𝐴). (C) (A) is true but (R) is false. (D) (A) is false but (𝑅) is true.Checking Assertion Assertion (A): The function 𝑓:𝑅−{(2𝑛+1)𝜋/2:𝑛∈𝑍}→(−∞,−1]∪[1,∞) defined by 𝑓(𝑥)=sec 𝑥 is not one-one function in its domain. Given 𝑓(𝑥)=sec𝑥 Now, sec〖𝜋/3〗=2 sec〖(−𝜋)/3〗=2 Also, sec〖5𝜋/3〗=2 sec〖(−5𝜋)/3〗=2 Since sec x = 2 is for more than one value of x ∴ 𝑓(𝑥)=sec𝑥 is not a one-one function ∴ Assertion is true Checking Reason Reason (R): The line 𝑦=2 meets the graph of the function at more than one point. Since 𝑓(𝑥)=sec 𝑥 Thus, 𝑦=2 means 𝐬𝐞𝐜 𝒙=𝟐 And sec x = 2 is true for x = 𝝅/𝟑,(−𝝅)/𝟑,𝟓𝝅/𝟑,(−𝟓𝝅)/𝟑… So, line 𝑦=2 meets the graph of f(x) at more than one point ∴ Reasoning is true Is Reason a Correct explanation for Assertion? Since sec x = 2 is for more than one value of x And, it means that line 𝑦=2 meets the graph of f(x) at more than one point Therefore, Reasoning is a correct explanation for Assertion So, Assertion is true Reasoning is true And, Reasoning is a correct explanation for Assertion So, the correct answer is (a)