BoardMaths

Continuity and Differentiability

17 Board Maths previous year questions on Continuity and Differentiability — options free on every question; 2 include the answer & explanation free, the rest unlock with PYQ Pass.

Q1 FREE PREVIEW
PYQ

If \({\mathrm{xe}}^{\mathrm{y}}=1\), then the value of \(\frac{\mathrm{dy}}{\mathrm{d}x}\) at \(\mathrm{x}=1\) is :

a

-1

b

1

c

\(-e\)

d

\(-\frac{1}{e}\)

✓ Correct answer: a)

-1

Explanation

\(\frac{d}{dx}\left(x{e}^{y}\right)=\frac{d}{dx}(1)\)

\({e}^{y}+x{e}^{y}\frac{dy}{dx}=0\)

\(\frac{dy}{dx}=\frac{-{e}^{y}}{x{e}^{y}}\)

\(\frac{dy}{dx}=-\frac{1}{x}\)

\({\left.\frac{dy}{dx}\right|}_{x=1}=-\frac{1}{1}=-1\)

Q2 FREE PREVIEW
PYQ

Question. Number of points of discontinuity of the function
\(f(x)=\frac{1}{x−5},x\neq 5\)
is :

a

1

b

2

c

3

d

5

✓ Correct answer: a)

1

ExplanationStep 1: Check for Points of Discontinuity

A function is discontinuous at points where:

  1. It is not defined.
  2. The left-hand limit (LHL) and right-hand limit (RHL) do not match or are not finite.

The given function is undefined at \(x=5\) as the denominator becomes zero, leading to an infinite discontinuity.

Step 2: Verify if There Are Other Discontinuities

The function is well-defined and continuous everywhere else because it is a simple rational function(except \(x=5\))

Step 3: Conclusion

Since there is only one point where the function is not defined (\(x=5\)x=5), the number of points of discontinuity is 1.

Q3
PYQ

The value of \(k\), for which \(\mathrm{f}\left(\mathrm{x}\right)=\left\{\begin{matrix}\frac{\sqrt{3}\mathrm{cosx}+\mathrm{sinx}}{3\mathrm{x}+\frac{\pi }{2}}, & \mathrm{x}\neq -\frac{\pi }{3} \\ \mathrm{k}, & \mathrm{x}=-\frac{\pi }{3}\end{matrix}\right.\) is continuous at \(\mathrm{x}=-\frac{\pi }{3}\), is :

a

0

b

\(-\frac{2}{3}\)

c

\(\frac{3}{2}\)

d

\(6\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q4
PYQ

Which of the following statements is true for the function \(f(x)=\left\{\begin{array}{cc}x^2+3, & x \neq 0 \\ 1, & x=0\end{array} ?\right.\)

a

\(\mathrm{f}(\mathrm{x})\) is continuous and differentiable \(\forall \mathrm{x} \in \mathbb{R}\)

b

\(\mathrm{f}(\mathrm{x})\) is continuous \(\forall \mathrm{x} \in \mathbb{R}\)

c

\(f(x)\) is continuous and differentiable \(\forall x \in \mathbb{R}-\{0\}\)

d

\(f(x)\) is discontinuous at infinitely many points

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q5
PYQ

The derivative of \(\tan ^{-1}\left(x^2\right)\) w.r.t. \(x\) is :

a

\(\frac{\mathrm{x}}{1+\mathrm{x}^4}\)

b

\(\frac{2 \mathrm{x}}{1+\mathrm{x}^4}\)

c

\(-\frac{2 x}{1+x^4}\)

d

\(\frac{1}{1+\mathrm{x}^4}\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q6
PYQ

The number of points of discontinuity of \(f(x)=\left\{\begin{aligned}|x|+3, & \text { if } x \leq-3 \\ -2 x, & \text { if }-3

a

0

b

1

c

2

d

infinite

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q7
PYQ

Derivative of \({\mathrm{e}}^{{\sin }^{2}x}\) with respect to \(\cos x\) is :

a

\(\sin x{\mathrm{e}}^{{\sin }^{2}x}\)

b

\(\cos x{\mathrm{e}}^{{\sin }^{2}x}\)

c

\(-2\cos x{\mathrm{e}}^{{\sin }^{2}x}\)

d

\(-2{\sin }^{2}x\cos x{\mathrm{e}}^{{\sin }^{2}x}\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q8
PYQ

The derivative of \(\sin \left(x^2\right)\) w.r.t. \(x\), at \(x=\sqrt{\pi}\) is :

a

1

b

-1

c

\(-2 \sqrt{\pi}\)

d

\(2 \sqrt{\pi}\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q9
PYQ

The value of k, for which \(\mathrm{f}\left(\mathrm{x}\right)=\left\{\begin{matrix}\frac{\sqrt{3}\mathrm{cosx}+\mathrm{sinx}}{3\mathrm{x}+\frac{\pi }{2}}, & \mathrm{x}\neq -\frac{\pi }{3} \\ \mathrm{k}, & \mathrm{x}=-\frac{\pi }{3}\end{matrix}\right.\) is continuous at \(\mathrm{x}=-\frac{\pi }{3}\), is :

a

0

b

\(-\frac{2}{3}\)

c

\(\frac{3}{2}\)

d

\(6\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q10
PYQ

The derivative of \(\sin \left(x^2\right)\) w.r.t. \(x\), at \(x=\sqrt{\pi}\) is :

a

1

b

-1

c

\(-2 \sqrt{\pi}\)

d

\(2 \sqrt{\pi}\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q11
PYQ

The number of points of discontinuity of \(f(x)=\left\{\begin{aligned}|x|+3, & \text { if } x \leq-3 \\ -2 x, & \text { if }-3

a

0

b

1

c

2

d

infinite

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q12
PYQ

If \({\mathrm{xe}}^{\mathrm{y}}=1\), then the value of \(\frac{\mathrm{dy}}{\mathrm{d}x}\) at \(\mathrm{x}=1\) is :

a

\(-1\)

b

1

c

\(-e\)

d

\(-\frac{1}{e}\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q13
PYQ

Which of the following statements is true for the function \(f(x)=\left\{\begin{array}{cc}x^2+3, & x \neq 0 \\ 1, & x=0\end{array} ?\right.\)

a

\(\mathrm{f}(\mathrm{x})\) is continuous and differentiable \(\forall \mathrm{x} \in \mathbb{R}\)

b

\(\mathrm{f}(\mathrm{x})\) is continuous \(\forall \mathrm{x} \in \mathbb{R}\)

c

\(f(x)\) is continuous and differentiable \(\forall x \in \mathbb{R}-\{0\}\)

d

\(f(x)\) is discontinuous at infinitely many points

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q14
PYQ

Derivative of \({\mathrm{e}}^{{\sin }^{2}x}\) with respect to \(\cos x\) is :

a

\(\sin x{\mathrm{e}}^{{\sin }^{2}x}\)

b

\(\cos x{\mathrm{e}}^{{\sin }^{2}x}\)

c

\(-2\cos x{\mathrm{e}}^{{\sin }^{2}x}\)

d

\(-2{\sin }^{2}x\cos x{\mathrm{e}}^{{\sin }^{2}x}\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q15
PYQ

Question. Number of points of discontinuity of the function
\(f(x)=\frac{1}{x−5},x\neq 5\)
is :

a

1

b

2

c

3

d

5

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q16
PYQ

The derivative of \(\tan ^{-1}\left(x^2\right)\) w.r.t. \(x\) is :

a

\(\frac{\mathrm{x}}{1+\mathrm{x}^4}\)

b

\(\frac{2 \mathrm{x}}{1+\mathrm{x}^4}\)

c

\(-\frac{2 x}{1+x^4}\)

d

\(\frac{1}{1+\mathrm{x}^4}\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149
Q17
PYQ

If \(y=x\cdot {\log }_{e}x\), then the value of \(\frac{{d}^{2}y}{d{x}^{2}}\) will be -

a

\(\frac{1}{1+x}\)

b

\(\frac{1}{x}\)

c

\({\log }_{e}(1+x)\)

d

\(1+{\log }_{e}x\)

🔒
Answer & explanation — PYQ Pass

Options are free to see. Unlock the correct answer and full explanation with Pass.

Unlock · ₹149

Practice more Board Maths PYQs

Browse every Maths chapter, or explore the full Board question bank.

All Maths chapters →