12th Standard CBSE Syllabus & Materials

12th Standard CBSE

CBSE 12th Economics Government Budget and the Economy Previous year Question Papers Study Material - QB365 Set A

NEW

12th Standard CBSE

CBSE 12th Computer Science Interface Python with MySQL - New Previous year Question Papers Study Material - QB365 Set A

NEW

12th Standard CBSE

CBSE 12th Computer Science Database Concept - New Previous year Question Papers Study Material - QB365 Set A

NEW

12th Standard CBSE

CBSE 12th Computer Science Data Communication - New Previous year Question Papers Study Material - QB365 Set A

NEW

12th Standard CBSE

CBSE 12th Computer Science Data Structures - New Previous year Question Papers Study Material - QB365 Set A

NEW

12th Standard CBSE

CBSE 12th Computer Science Functions - New Previous year Question Papers Study Material - QB365 Set A

CBSE 12th Standard Maths Subject Application of Derivatives Ncert Exemplar MCQ Questions 2021

Published on: 24/05/2021

QB365 Provides the updated NCERT Examplar Questions for Class 12 Maths, and also provide the detail solution for each and every ncert examplar questions , QB365 will give all kind of study materials will help to get more marks

Download CBSE Class 12th Standard CBSE Maths question papers, sample papers, important questions, and previous year solved papers in PDF format. Get free study materials, NCERT solutions, and exam preparation resources for Class 12th Standard CBSE Maths

Questions + Answers key

Take MCQ Maths Test

QB365 Student Learing Managemnet System

Std: 12th Standard CBSE - Maths

chapter: - NCERT Exemplers

Visit QB365-SLMS - https://www.qb365.in/slms/ Complete Questions and Answers

Questions:

Multiple Choice Question

4 x 1 = 4

Which of the following functions is decreasing on \(\left(0, \frac{\pi}{2}\right)\)?

(a)

sin2x

(b)

tanx

(c)

cosx

(d)

cos3x

The function \(f(x)=\tan x-x\)

(a)

always increases

(b)

always decreases

(c)

never increases

(d)

sometimes increases and sometimes decreases

If \(y=x(x-3)^{2}\) decreases for the values of x given by

(a)

\(1<x<3\)

(b)

\(x<0\)

(c)

\(x>0\)

(d)

\(0<x<\frac{3}{2}\)

A ladder, 5 m long, standing on a horizontal floor, leans against a vertical wall. If the top of the ladder slides downwards at the rate of 10 cm/s, then the rate at which the angle between the floor and the ladder is decreasing when lower end of ladder is 2 m from the wall is

(a)

\(\frac{1}{10} \mathrm{rad} / \mathrm{s}\)

(b)

\(\frac{1}{20} \mathrm{rad} / \mathrm{s}\)

(c)

\(20 \mathrm{rad} / \mathrm{s}\)

(d)

10 rad/s

Visit QB365-SLMS - https://www.qb365.in/slms/

Answers Key:

Multiple Choice Question

4 x 1 = 4

In the interval \(\left(0, \frac{\pi}{2}\right), f(x)=\cos x\)
\(\Rightarrow \quad f^{\prime}(x)=-\sin x\)
which gives \(f^{\prime}(x)<0 \text { in }\left(0, \frac{\pi}{2}\right)\)
Hence, f(x) = cos x is decreasing in \(\left(0, \frac{\pi}{2}\right)\)

We have, f(x) = tan x - x
\(\therefore \quad f^{\prime}(x)=\sec ^{2} x-1 \Rightarrow f^{\prime}(x) \geq 0, \forall x \in R\)
So, f(x) always increases

We have,\(y=x(x-3)^{2}\)
\( \therefore \quad \frac{d y}{d x} =x \cdot 2(x-3) \cdot 1+(x-3)^{2} \cdot 1 \\ =2 x^{2}-6 x+x^{2}+9-6 x=3 x^{2}-12 x+9 \\ =3\left(x^{2}-3 x-x+3\right)=3(x-3)(x-1) \)
So, y = x(x - 3)² decreases for (1, 3).
[since, y' < 0 for all x E (1,3), hence y is decreasing on (1, 3)]