Class 12 Maths Chapter 2: Inverse Trigonometric Functions Assertion-reason questions with answers
2 assertion-reason questions on Inverse Trigonometric Functions, each with its answer and the reason, written from the NCERT chapter. For the CBSE board and JEE Main, which are set from the same NCERT chapter. Open a question's solution to check your working; then take the free test to find your next chapter. Each question gives an Assertion (A) and a Reason (R); choose how they stand to each other.
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Answer: (a) Both A and R are true, and R is the correct explanation of A.
−π/4 is outside [0, π], so the answer is not −π/4; replacing −π/4 by π/4, which has the same cosine and lies in the branch, gives π/4. R gives exactly this reason.
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Answer: (b) Both A and R are true, but R is not the correct explanation of A.
A is true: the domain of sec⁻¹ is R − (−1, 1), and 1/2 lies in (−1, 1). R is a true fact about the range, but A follows from the domain, not the range, so R does not explain A.