



CBSE Class 12 Sample Paper for 2025 Boards
CBSE Class 12 Sample Paper for 2025 Boards
Last updated at Feb. 12, 2025 by Teachoo
Transcript
Question 20 Statement A Assertion (A): The function ๐:๐ โ{(2๐+1)๐/2:๐โ๐}โ(โโ,โ1]โช[1,โ) defined by ๐(๐ฅ)=sec ๐ฅ is not one-one function in its domain. Statement R Reason (R): The line ๐ฆ=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 ( ๐ ) are true but (๐ ) is not the correct explanation of (๐ด). (C) (A) is true but (R) is false. (D) (A) is false but (๐ ) is true.Checking Assertion Assertion (A): The function ๐:๐ โ{(2๐+1)๐/2:๐โ๐}โ(โโ,โ1]โช[1,โ) defined by ๐(๐ฅ)=sec ๐ฅ is not one-one function in its domain. Given ๐(๐ฅ)=secโก๐ฅ Now, secโกใ๐/3ใ=2 secโกใ(โ๐)/3ใ=2 Also, secโกใ5๐/3ใ=2 secโกใ(โ5๐)/3ใ=2 Since sec x = 2 is for more than one value of x โด ๐(๐ฅ)=secโก๐ฅ is not a one-one function โด Assertion is true Checking Reason Reason (R): The line ๐ฆ=2 meets the graph of the function at more than one point. Since ๐(๐ฅ)=sec ๐ฅ Thus, ๐ฆ=2 means ๐ฌ๐๐ ๐=๐ And sec x = 2 is true for x = ๐ /๐,(โ๐ )/๐,๐๐ /๐,(โ๐๐ )/๐โฆ So, line ๐ฆ=2 meets the graph of f(x) at more than one point โด 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 ๐ฆ=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)