Mathematics · Class 11 Science
Ch 10Differential Calculus – Differentiability and Methods of Differentiation — Class 11 Mathematics, concept-first.
Everyone has an intuitive sense of speed as "distance covered per unit time," but that intuition is really about average speed. If a bus covers km in one hour, its average velocity for the trip is km/h — yet it plainly slows in towns and speeds up on open stretches, so the actual velocity keeps changing.
Key concepts
Hover a concept to preview it and jump to its most relevant Q&A.
The Derivative — Definition
The derivative grew out of two of the four classic 17th-century calculus problems: the tangent line problem and the velocity problem. Both reduce to the same limiting construction.
Most relevant Q&A
Chapter contents
The NCERT structure, section by section. Open a section to see its questions, then read the concept-first solution.
Introduction
Everyone has an intuitive sense of speed as "distance covered per unit time," but that intuition is really about average speed.
The concept of derivative
Calculus, as a discipline, grew out of four major problems seventeenth-century mathematicians were wrestling with:
The tangent line problem
For a circle, "the tangent at " has a clean, purely geometric meaning: it is the line through perpendicular to the radius at (Fig. 10.1).
Velocity of Rectilinear motion
The same secant-to-tangent limiting idea solves the velocity problem. Suppose an object moves along a straight line with position (signed distance from the origin) at time ; is called the position fun…
The derivative of a Function
The limit that produced both the tangent slope and the instantaneous velocity is important enough to deserve its own name and its own general definition, independent of any particular geometric or phy…
One sided derivatives (left hand and right hand derivatives)
Definition 10.2's limit is two-sided — from both directions at once must give the same value. Splitting it into its two one-sided pieces is what lets us pin down exactly where and why a derivative can…
Differentiability and Continuity
The definitions above raise an obvious question: can a function be continuous at a point yet still fail to have a derivative there? The book answers this with a sequence of illustrations before provin…
+−Exercise 10.1i7 questions
- Q1Find the derivatives of the following functions using first principle. (i) $f(x) = 6$ (ii) $f(x) = -4x + 7$ (iii) $f(x) = -x^2 + 2$Free
- Q2Find the derivatives from the left and from the right at $x = 1$ (if they exist) of the following functions. Are the functions differentiabl…Free
- Q3Determine whether the following function is differentiable at the indicated values. (i) $f(x) = x\,|x|$ at $x = 0$ (ii) $f(x) = |x^2 - 1|$ a…Free
- Q4Show that the following functions are not differentiable at the indicated value of $x$. (i) $f(x) = \begin{cases} -x+2, & x \le 2 \\ 2x-4, &…Preview
- Q5The graph of $f$ is shown below (Fig. 10.24). State with reasons the $x$ values (the numbers) at which $f$ is not differentiable. *Graph des…Preview
- Q6If $f(x) = |x+100| + x^2$, test whether $f'(-100)$ exists.Preview
- Q7Examine the differentiability of the following functions in $\mathbb{R}$ by drawing the diagrams. (i) $|\sin x|$ (ii) $|\cos x|$Preview
Differentiation Rules
Computing every derivative directly from Definition 10.2's limit — "from first principle" — is correct but, as the book notes, "extremely laborious and difficult...
Derivatives of basic elementary functions
With the general rules of §10.4 in hand, we now derive — once, from first principle, each time using the -form — the derivatives of every basic elementary function.
+−Exercise 10.2i20 questions
- Q1Find the derivative of the following function with respect to the corresponding independent variable: $f(x) = x - 3\sin x$Free
- Q2Find the derivative of the following function with respect to the corresponding independent variable: $y = \sin x + \cos x$Free
- Q3Find the derivative of the following function with respect to the corresponding independent variable: $f(x) = x \sin x$Free
- Q4Find the derivative of the following function with respect to the corresponding independent variable: $y = \cos x - 2\tan x$Preview
- Q5Find the derivative of the following function with respect to the corresponding independent variable: $g(t) = t^3\cos t$Preview
- Q6Find the derivative of the following function with respect to the corresponding independent variable: $g(t) = 4\sec t + \tan t$Preview
- Q7Find the derivative of the following function with respect to the corresponding independent variable: $y = e^x \sin x$Preview
- Q8Find the derivative of the following function with respect to the corresponding independent variable: $y = \dfrac{\tan x}{x}$Preview
- Q9Find the derivative of the following function with respect to the corresponding independent variable: $y = \dfrac{\sin x}{1+\cos x}$Preview
- Q10Find the derivative of the following function with respect to the corresponding independent variable: $y = \dfrac{x}{\sin x + \cos x}$Preview
- Q11Find the derivative of the following function with respect to the corresponding independent variable: $y = \dfrac{\tan x - 1}{\sec x}$Preview
- Q12Find the derivative of the following function with respect to the corresponding independent variable: $y = \dfrac{\sin x}{x^2}$Preview
- Q13Find the derivative of the following function with respect to the corresponding independent variable: $y = \tan\theta(\sin\theta + \cos\thet…Preview
- Q14Find the derivative of the following function with respect to the corresponding independent variable: $y = \operatorname{cosec} x \cdot \cot…Preview
- Q15Find the derivative of the following function with respect to the corresponding independent variable: $y = x \sin x \cos x$Preview
- Q16Find the derivative of the following function with respect to the corresponding independent variable: $y = e^{-x} \cdot \log x$Preview
- Q17Find the derivative of the following function with respect to the corresponding independent variable: $y = (x^2+5)\log(1+x)\,e^{-3x}$Preview
- Q18Find the derivative of the following function with respect to the corresponding independent variable: $y = \sin x^{\circ}$Preview
- Q19Find the derivative of the following function with respect to the corresponding independent variable: $y = \log_{10} x$Preview
- Q20Draw the graph of $f'(x)$ if $f(x) = 2x^2 - 5x + 3$.Preview
Examples on Chain Rule
This section is pure practice at recognising the outer function / inner function split that the chain rule (Theorem 10.5) needs, and at combining it with the other rules when several layers or several…
+−Exercise 10.3i30 questions
- Q1Differentiate the following: $y = (x^2+4x+6)^5$Free
- Q2Differentiate the following: $y = \tan 3x$Free
- Q3Differentiate the following: $y = \cos(\tan x)$Free
- Q4Differentiate the following: $y = \sqrt[3]{1+x^3}$Preview
- Q5Differentiate the following: $y = e^{\sqrt{x}}$Preview
- Q6Differentiate the following: $y = \sin(e^x)$Preview
- Q7Differentiate the following: $F(x) = (x^3+4x)^7$Preview
- Q8Differentiate the following: $h(t) = \left(t - \dfrac{1}{t}\right)^{3/2}$Preview
- Q9Differentiate the following: $f(t) = \sqrt[3]{1+\tan t}$Preview
- Q10Differentiate the following: $y = \cos(a^3+x^3)$Preview
- Q11Differentiate the following: $y = e^{-mx}$Preview
- Q12Differentiate the following: $y = 4\sec 5x$Preview
- Q13Differentiate the following: $y = (2x-5)^4(8x^2-5)^{-3}$Preview
- Q14Differentiate the following: $y = (x^2+1)\sqrt[3]{x^2+2}$Preview
- Q15Differentiate the following: $y = xe^{-x^2}$Preview
- Q16Differentiate the following: $s(t) = \sqrt[4]{\dfrac{t^3+1}{t^3-1}}$Preview
- Q17Differentiate the following: $f(x) = \dfrac{x}{\sqrt{7-3x}}$Preview
- Q18Differentiate the following: $y = \tan(\cos x)$Preview
- Q19Differentiate the following: $y = \dfrac{\sin^2 x}{\cos x}$Preview
- Q20Differentiate the following: $y = 5^{-1/x}$Preview
- Q21Differentiate the following: $y = \sqrt{1+2\tan x}$Preview
- Q22Differentiate the following: $y = \sin^3 x + \cos^3 x$Preview
- Q23Differentiate the following: $y = \sin^2(\cos kx)$Preview
- Q24Differentiate the following: $y = (1+\cos^2 x)^6$Preview
- Q25Differentiate the following: $y = \dfrac{e^{3x}}{1+e^x}$Preview
- Q26Differentiate the following: $y = \sqrt{x+\sqrt{x}}$Preview
- Q27Differentiate the following: $y = e^{x\cos x}$Preview
- Q28Differentiate the following: $y = \sqrt{x+\sqrt{x+\sqrt{x}}}$Preview
- Q29Differentiate the following: $y = \sin\!\big(\tan(\sqrt{\sin x})\big)$Preview
- Q30Differentiate the following: $y = \sin^{-1}\!\left(\dfrac{1-x^2}{1+x^2}\right)$Preview
Implicit Differentiation
A function in which the dependent variable is expressed solely in terms of the independent variable , i.e. , is called an explicit function — for instance .
Logarithmic Differentiation
Ordinary differentiation rules — the power rule, the exponential rule — each handle only one specific relationship between the base and the exponent (a fixed power of a variable base, or a fixed base…
Substitution method
Some inverse-trigonometric expressions can in principle be differentiated directly by repeated chain-rule and quotient-rule work, but that route is often extremely laborious.
Derivatives of variables defined by parametric equations
So far has been expressed either explicitly in terms of , or implicitly via an equation directly relating and .
Differentiation of one function with respect to another function
The chain rule (Theorem 10.5) differentiates a composite function with respect to the independent variable .
Higher order Derivatives
53 QIf is the position (displacement) of an object moving along a straight line, its first derivative already has a direct physical meaning: the velocity — this is exactly the instantaneous velocity defin…
+−Exercise 10.4i28 questions
- Q1Find the derivative of the following: $y = x^{\cos x}$Free
- Q2Find the derivative of the following: $y = x^{\log x} + (\log x)^x$Free
- Q3Find the derivative of the following: $\sqrt{xy} = e^{(x-y)}$Free
- Q4Find the derivative of the following: $x^y = y^x$Preview
- Q5Find the derivative of the following: $(\cos x)^{\log x}$Preview
- Q6Find the derivative of the following: $\dfrac{x^2}{a^2}+\dfrac{y^2}{b^2}=1$Preview
- Q7Find the derivative of the following: $\sqrt{x^2+y^2} = \tan^{-1}\!\left(\dfrac{y}{x}\right)$Preview
- Q8Find the derivative of the following: $\tan(x+y)+\tan(x-y) = x$Preview
- Q9If $\cos(xy) = x$, show that $\dfrac{dy}{dx} = \dfrac{-(1+y\sin(xy))}{x\sin(xy)}$.Preview
- Q10Find the derivative of the following: $\tan^{-1}\sqrt{\dfrac{1-\cos x}{1+\cos x}}$Preview
- Q11Find the derivative of the following: $\tan^{-1}\!\left(\dfrac{6x}{1-9x^2}\right)$Preview
- Q12Find the derivative of the following: $\cos\!\left(2\tan^{-1}\sqrt{\dfrac{1-x}{1+x}}\right)$Preview
- Q13Find the derivative of the following: $x = a\cos^3 t\ ;\ y = a\sin^3 t$Preview
- Q14Find the derivative of the following: $x = a(\cos t + t\sin t)\ ;\ y = a(\sin t - t\cos t)$Preview
- Q15Find the derivative of the following: $x = \dfrac{1-t^2}{1+t^2},\ y = \dfrac{2t}{1+t^2}$Preview
- Q16Find the derivative of the following: $\cos^{-1}\!\left(\dfrac{1-x^2}{1+x^2}\right)$Preview
- Q17Find the derivative of the following: $\sin^{-1}(3x-4x^3)$Preview
- Q18Find the derivative of the following: $\tan^{-1}\!\left(\dfrac{\cos x + \sin x}{\cos x - \sin x}\right)$Preview
- Q19Find the derivative of $\sin x^2$ with respect to $x^2$.Preview
- Q20Find the derivative of $\sin^{-1}\!\left(\dfrac{2x}{1+x^2}\right)$ with respect to $\tan^{-1}x$.Preview
- Q21If $u = \tan^{-1}\dfrac{\sqrt{1+x^2}-1}{x}$ and $v = \tan^{-1}x$, find $\dfrac{du}{dv}$.Preview
- Q22Find the derivative of $\tan^{-1}\!\left(\dfrac{\sin x}{1+\cos x}\right)$ with respect to $\tan^{-1}\!\left(\dfrac{\cos x}{1+\sin x}\right)$…Preview
- Q23If $y = \sin^{-1}x$ then find $y''$.Preview
- Q24If $y = e^{\tan^{-1}x}$, show that $(1+x^2)y'' + (2x-1)y' = 0$.Preview
- Q25If $y = \dfrac{\sin^{-1}x}{\sqrt{1-x^2}}$, show that $(1-x^2)y_2 - 3xy_1 - y = 0$.Preview
- Q26If $x = a(\theta+\sin\theta),\ y = a(1-\cos\theta)$ then prove that at $\theta = \dfrac{\pi}{2}$, $y'' = \dfrac{1}{a}$.Preview
- Q27If $\sin y = x\sin(a+y)$, then prove that $\dfrac{dy}{dx} = \dfrac{\sin^2(a+y)}{\sin a}$, $a\ne n\pi$.Preview
- Q28If $y = (\cos^{-1}x)^2$, prove that $(1-x^2)\dfrac{d^2y}{dx^2} - x\dfrac{dy}{dx} - 2 = 0$. Hence find $y_2$ when $x=0$.Preview
+−Exercise 10.5i25 questions
- Q1$\dfrac{d}{dx}\left(\dfrac{2}{\pi}\sin x^{\circ}\right)$ is (1) $\dfrac{\pi}{180}\cos x^{\circ}$ (2) $\dfrac{1}{90}\cos x^{\circ}$ (3) $\dfr…Free
- Q2If $y = f(x^2+2)$ and $f'(3) = 5$, then $\dfrac{dy}{dx}$ at $x=1$ is (1) 5 (2) 25 (3) 15 (4) 10Free
- Q3If $y = \dfrac14 u^4$, $u = \dfrac23 x^3+5$, then $\dfrac{dy}{dx}$ is (1) $\dfrac{1}{27}x^2(2x^3+15)^3$ (2) $\dfrac{2}{27}x(2x^3+5)^3$ (3) $…Free
- Q4If $f(x) = x^2-3x$, then the points at which $f(x) = f'(x)$ are (1) both positive integers (2) both negative integers (3) both irrational (4…Preview
- Q5If $y = \dfrac{1}{a-z}$, then $\dfrac{dz}{dy}$ is (1) $(a-z)^2$ (2) $-(z-a)^2$ (3) $(z+a)^2$ (4) $-(z+a)^2$Preview
- Q6If $y = \cos(\sin x^2)$, then $\dfrac{dy}{dx}$ at $x = \sqrt{\dfrac{\pi}{2}}$ is (1) $-2$ (2) $2$ (3) $-2\sqrt{\dfrac{\pi}{2}}$ (4) $0$Preview
- Q7If $y = mx+c$ and $f(0) = f'(0) = 1$, then $f(2)$ is (1) 1 (2) 2 (3) 3 (4) $-3$Preview
- Q8If $f(x) = x\tan^{-1}x$, then $f'(1)$ is (1) $1+\dfrac{\pi}{4}$ (2) $\dfrac12+\dfrac{\pi}{4}$ (3) $\dfrac12-\dfrac{\pi}{4}$ (4) $2$Preview
- Q9$\dfrac{d}{dx}\left(e^{x+5\log x}\right)$ is (1) $e^x\cdot x^4(x+5)$ (2) $e^x\cdot x(x+5)$ (3) $e^x+\dfrac{5}{x}$ (4) $e^x-\dfrac{5}{x}$Preview
- Q10If the derivative of $(ax-5)e^{3x}$ at $x=0$ is $-13$, then the value of $a$ is (1) 8 (2) $-2$ (3) 5 (4) 2Preview
- Q11If $x = \dfrac{1-t^2}{1+t^2},\ y = \dfrac{2t}{1+t^2}$ then $\dfrac{dy}{dx}$ is (1) $-\dfrac{y}{x}$ (2) $\dfrac{y}{x}$ (3) $-\dfrac{x}{y}$ (4…Preview
- Q12If $x = a\sin\theta$ and $y = b\cos\theta$, then $\dfrac{d^2y}{dx^2}$ is (1) $\dfrac{a}{b^2}\sec^2\theta$ (2) $-\dfrac{b}{a}\sec^2\theta$ (3…Preview
- Q13The differential coefficient of $\log_{10}x$ with respect to $\log_x 10$ is (1) 1 (2) $-(\log_{10}x)^2$ (3) $(\log_x 10)^2$ (4) $\dfrac{x^2}…Preview
- Q14If $f(x) = x+2$, then $f'(f(x))$ at $x=4$ is (1) 8 (2) 1 (3) 4 (4) 5Preview
- Q15If $y = \dfrac{(1-x)^2}{x^2}$, then $\dfrac{dy}{dx}$ is (1) $\dfrac{2}{x^2}+\dfrac{2}{x^3}$ (2) $-\dfrac{2}{x^2}+\dfrac{2}{x^3}$ (3) $-\dfra…Preview
- Q16If $pv = 81$, then $\dfrac{dp}{dv}$ at $v=9$ is (1) 1 (2) $-1$ (3) 2 (4) $-2$Preview
- Q17If $f(x) = \begin{cases} x-5, & x\le 1 \\ 4x^2-9, & 1<x<2 \\ 3x+4, & x\ge 2 \end{cases}$, then the right hand derivative of $f(x)$ at $x=2$…Preview
- Q18It is given that $f'(a)$ exists, then $\displaystyle\lim_{x\to a}\dfrac{xf(a)-af(x)}{x-a}$ is (1) $f(a)-af'(a)$ (2) $f'(a)$ (3) $-f'(a)$ (4)…Preview
- Q19If $f(x) = \begin{cases} x+1, & x<2 \\ 2x-1, & x\ge 2 \end{cases}$, then $f'(2)$ is (1) 0 (2) 1 (3) 2 (4) does not existPreview
- Q20If $g(x) = (x^2+2x+3)f(x)$ and $f(0) = 5$ and $\displaystyle\lim_{x\to0}\dfrac{f(x)-5}{x}=4$, then $g'(0)$ is (1) 20 (2) 14 (3) 18 (4) 12Preview
- Q21If $f(x) = \begin{cases} x+2, & -1<x<3 \\ 5, & x=3 \\ 8-x, & x>3 \end{cases}$, then at $x=3$, $f'(x)$ is (1) 1 (2) $-1$ (3) 0 (4) does not e…Preview
- Q22The derivative of $f(x) = x|x|$ at $x=-3$ is (1) 6 (2) $-6$ (3) does not exist (4) 0Preview
- Q23If $f(x) = \begin{cases} 2a-x, & -a<x<a \\ 3x-2a, & x\ge a \end{cases}$, then which one of the following is true? (1) $f(x)$ is not differen…Preview
- Q24If $f(x) = \begin{cases} ax^2-b, & -1<x<1 \\ \dfrac{1}{|x|}, & \text{elsewhere} \end{cases}$ is differentiable at $x=1$, then (1) $a=\dfrac1…Preview
- Q25The number of points in $\mathbb{R}$ in which the function $f(x) = |x-1|+|x-3|+\sin x$ is not differentiable, is (1) 3 (2) 2 (3) 1 (4) 4Preview
Sample & Board Papers
Sample papers and previous-year board questions for this subject.
+−Show 33 questionsHide questions33 questions
- Q1Which of the function is not differentiable? (a) $f(x) = \sin x + \cos x$ in $(-\infty, \infty)$ (b) $f(x) = \sin x$ in $(-\infty, \infty)$…Preview
- Q2Find $f'(x)$, if $f(x) = \sin|x|$, by removing the modulus sign.Preview
- Q3Find $\dfrac{dy}{dx}$ if $\tan(x+y) + \tan(x-y) = 1$.Preview
- Q4(a) Draw the graph of the function $f(x) = \begin{cases} 2x, & x<1 \\ 2, & x=1 \\ x+1, & x>1 \end{cases}$ and state the differentiability at…Preview
- Q5If $f(x)=\begin{cases}2a-x, & -a<x<a\\ 3x-2a, & x\ge a\end{cases}$ then which one of the following is true? (a) $f(x)$ is continuous for all…Preview
- Q6If $f(x)=x^2-3x$, then the points at which $f(x)=f'(x)$ are: (a) both irrational (b) one rational and another irrational (c) both positive i…Preview
- Q7Differentiate: $y=\sin^{-1}\left(\dfrac{1-x^2}{1+x^2}\right)$Preview
- Q8Find $\dfrac{dy}{dx}$ if $x=a(t-\sin t)$, $y=a(1-\cos t)$.Preview
- Q9(a) Find $\dfrac{d^2y}{dx^2}$ if $x^2+y^2=4$. **OR** (b) The chances of X, Y and Z becoming managers of a certain company are 4 : 2 : 3. The…Preview
- Q10The number of points in $\mathbf{R}$ in which the function $f(x) = |x-1| + |x-3| + \sin x$ is not differentiable, is: (a) 3 (b) 2 (c) 1 (d)…Preview
- Q11If $f(x) = x\tan^{-1}x$ then, $f'(0) + f'(1)$ is: (a) $1 + \dfrac{\pi}{4}$ (b) $\dfrac{1}{2} + \dfrac{\pi}{4}$ (c) $\dfrac{1}{2} - \dfrac{\p…Preview
- Q12Differentiate $y = \dfrac{x}{1+\tan x}$ with respect to '$x$'.Preview
- Q13If $y = \tan^{-1}\left(\dfrac{1-x^2}{1+x^2}\right)$ find $y'$.Preview
- Q14If $y=f(x^2+2)$ and $f'(3)=5$ then, $\dfrac{dy}{dx}$ at $x=1$ is: (a) 15 (b) 5 (c) 10 (d) 25Preview
- Q15If $f(x) = \begin{cases} x+2, & -1<x<3 \\ 5, & x=3 \\ 8-x, & x>3 \end{cases}$, then at $x=3$, $f'(x)$ is: (a) 0 (b) 1 (c) does not exist (d)…Preview
- Q16Differentiate $y=x^3+5x^2+3x+7$ with respect to $x$.Preview
- Q17Find $\dfrac{dy}{dx}$ if $x^2+y^2=1$.Preview
- Q18If $f(x) = mx + c$ and $f(0) = f'(0) = 1$ then $f(3)$ is: (a) 3 (b) 1 (c) 4 (d) 2Preview
- Q19Find $\sqrt[3]{1001}$ approximately (two decimal places).Preview
- Q20Differentiate with respect to $x$. $y = \dfrac{\cos x}{x^3}$Preview
- Q21If $y=f(x^2+2)$ and $f'(3)=5$, then $\dfrac{dy}{dx}$ at $x=1$ is: (a) $15$ (b) $5$ (c) $10$ (d) $25$Preview
- Q22If $y=e^{\sin x}$ then $\dfrac{dy}{dx}=$ (a) $\sin x\,e^{\sin x}$ (b) $e^{\sin x}$ (c) $\cos x\,e^{\sin x}$ (d) $e^{\cos x}$Preview
- Q23Find $f''$ if $f(x)=x\cos x$.Preview
- Q24Differentiate the following with respect to $x$. $y=xe^x\log x$Preview
- Q25The derivative of $f(x) = x|x|$ at $x = -3$ is: (a) does not exist (b) $6$ (c) $0$ (d) $-6$Preview
- Q26$\dfrac{d}{dx}\left(\dfrac{2}{\pi}\sin x^\circ\right)$ is: (a) $\dfrac{\pi}{90}\cos x^\circ$ (b) $\dfrac{\pi}{180}\cos x^\circ$ (c) $\dfrac{…Preview
- Q27Differentiate : $y = e^{\sin x}$Preview
- Q28Find $\dfrac{dy}{dx}$, if $y = \cos^{-1}(2\cos^2 x - 1)$Preview
- Q29If $y = mx + c$ and $f(0) = f'(0) = 1$, then $f(2)$ is: (a) 3 (b) 1 (c) -3 (d) 2Preview
- Q30Find $f'(7)$ if $f(x) = |x - 5|$ (a) -1 (b) 1 (c) 5 (d) 7Preview
- Q31Find the value of $\sqrt[3]{65}$Preview
- Q32Find $\dfrac{dy}{dx}$ if $x=a(t-\sin t)$, $y=a(1-\cos t)$Preview
- Q33If $y=e^{\tan^{-1}x}$, show that $(1+x^2)y''+(2x-1)y'=0$ **OR** Show that $\begin{vmatrix}b+c & a-c & a-b\\ b-c & c+a & b-a\\ c-b & c-a & a+…Preview