NCERT Solutions
Class 12 - Mathematics Part-1 - Chapter 5: CONTINUITY AND DIFFERENTIABILITY
Exercise 5.7

Question. 1

Find the second order derivative of the function \(y = x^2 + 3x + 2\).

Answer:

\(\dfrac{d^2y}{dx^2} = 2\)

Question. 2

Find the second order derivative of the function \(y = x^{20}\).

Answer:

\(\dfrac{d^2y}{dx^2} = 380x^{18}\)

Question. 3

Find the second order derivative of the function \(y = x\cdot \cos x\).

Answer:

\(\dfrac{d^2y}{dx^2} = -x\cos x - 2\sin x\)

Question. 4

Find the second order derivative of the function \(y = \log x\).

Answer:

\(\dfrac{d^2y}{dx^2} = -\dfrac{1}{x^2}\)

Question. 5

Find the second order derivative of the function \(y = x^3\log x\).

Answer:

\(\dfrac{d^2y}{dx^2} = x(5 + 6\log x)\)

Question. 6

Find the second order derivative of the function \(y = e^x\sin 5x\).

Answer:

\(\dfrac{d^2y}{dx^2} = 2e^x(5\cos 5x - 12\sin 5x)\)

Question. 7

Find the second order derivative of the function \(y = e^{6x}\cos 3x\).

Answer:

\(\dfrac{d^2y}{dx^2} = 9e^{6x}(3\cos 3x - 4\sin 3x)\)

Question. 8

Find the second order derivative of the function \(y = \tan^{-1}x\).

Answer:

\(\dfrac{d^2y}{dx^2} = -\dfrac{2x}{(1 + x^2)^2}\)

Question. 9

Find the second order derivative of the function \(y = \log(\log x)\).

Answer:

\(\dfrac{d^2y}{dx^2} = -\dfrac{1 + \log x}{(x\log x)^2}\)

Question. 10

Find the second order derivative of the function \(y = \sin(\log x)\).

Answer:

\(\dfrac{d^2y}{dx^2} = -\dfrac{\sin(\log x) + \cos(\log x)}{x^2}\)

Question. 12

If \(y = \cos^{-1}x\), find \(\dfrac{d^2y}{dx^2}\) in terms of \(y\) alone.

Answer:

\(\dfrac{d^2y}{dx^2} = -\cot y\,\cosec^2 y\)

NCERT Solutions Class 12 – Mathematics Part-1 – Chapter 5: CONTINUITY AND DIFFERENTIABILITY – Exercise 5.7 | Detailed Answers