CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1)
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CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1)
Last updated at August 10, 2026 by Teachoo
This question is inspired from Ex 5.7, 11 - Chapter 5 Class 12 - Continuity and Differentiability
Transcript
Question 14 If y = 5 cos x β 3 sin x, then (π^2 π¦)/(ππ₯^2 ) is equal to: (a) βy (b) y (c) 25y (d) 9y y = 5 cosβ‘γπ₯β3 sinβ‘π₯ γ Differentiating π€.π.π‘.π₯ ππ¦/ππ₯ = (π(5 cosβ‘γπ₯β3 sinβ‘π₯ γ))/ππ₯ ππ¦/ππ₯ = (π(5 cosβ‘π₯))/ππ₯ β (π(3 sinβ‘π₯))/ππ₯ π π/π π = β 5 πππβ‘π β 3 πππβ‘π Again Differentiating π€.π.π‘.π₯ π/ππ₯ (ππ¦/ππ₯) = (π γ(β 5 sinγβ‘π₯ γβ 3cosγβ‘γπ₯)γ)/ππ₯ (π^2 π¦)/(ππ₯^2 ) = β(π(5 sinβ‘π₯))/ππ₯ β (π(3 cosβ‘π₯))/ππ₯ (π^2 π¦)/(ππ₯^2 ) = β 5 cosβ‘π₯ β 3 γ(βsinγβ‘γπ₯)γ (π^2 π¦)/(ππ₯^2 ) = β 5 cosβ‘π₯ + 3 sinβ‘π₯ (π^2 π¦)/(ππ₯^2 ) = β (5 πππβ‘π β 3 πππβ‘π) (π ^π π)/(π π^π ) = βy So, the correct answer is (A)
