PYQ Vault

Day 146: CBSE Class 12 Maths

5 questions. Try each one first, then open its answer.

  1. Question 1

    Application of Derivatives. Asked once: 2026 (same type asked 3 times)

    23
    Find the sub-interval of (0,∞)(0, \infty) in which f(x)=xlog⁡xf(x) = x \log x is increasing.

  2. Question 2

    Application of Derivatives. Asked once: 2025 (same type asked 3 times)

    23
    Find the interval in which f(x)=x+1xf(x) = x + \dfrac{1}{x} is always increasing, x≠0x \ne 0.

  3. Question 3

    Application of Derivatives. Asked once: 2023 (same type asked 3 times)

    23
    If f(x) = a(tan x −- cot x), where a > 0, then find whether f(x) is increasing or decreasing function in its domain.

  4. Question 4

    Application of Derivatives. Asked once: 2026 (same type asked 3 times)

    6
    The surface area of a sphere when its volume changes at the same rate as its radius is :

    Tap an option to check your answer.

  5. Question 5

    Application of Derivatives. Asked once: 2023 (same type asked 3 times)

    25
    If the circumference of circle is increasing at the constant rate, prove that rate of change of area of circle is directly proportional to its radius.