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CBSE Class 12 Mathematics 2026 Main Paper 65(B) · Q191 Marksmonotonicity

CBSE Class 12 Mathematics 2026 Main Paper 65(B) · Question 19 (Applications Of Derivatives)

Assertion: e⁻ˣ decreases on ℝ. Reason: A function with negative derivative on an interval decreases there.

(A) Both true, and the reason explains the assertion.
(B) Both true, but the reason does not explain the assertion.
(C) Assertion true, reason false.
(D) Assertion false, reason true.

✅ Step-by-Step Solution

Final Answer: Both true, and the reason explains the assertion.

Its derivative −e⁻ˣ is negative everywhere, so the stated criterion applies.

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