CBSE > Class 12 > Mathematics | CBSE Board | Homework Help

Consider the given events
A = Numbers appearing on two dice are different
B = The sum of the numbers on two dice is 4

Clearly,
A = {(1, 2), (1, 3), (1, 4), (1, 5), (1, 6),
                     (2, 1), (2, 3), (2, 4), (2, 5), (2, 6),
                     (3, 1), (3, 2), (3, 4), (3, 5), (3, 6)
                     (4, 1), (4, 2), (4, 3), (4, 5), (4, 6),
                     (5, 1), (5, 2), (5, 3), (5, 4), (5, 6),
                     (6, 1), (6, 2), (6, 3), (6, 4), (6, 5)}
B = {(1, 3), (3, 1) and (2, 2)}

Now ,

A∩B={(1,3) and (3,1)}

∴ Required probability =P(B/A) = n(A∩B) / n(A) = 2 / 30 =1 / 15

0Thank You

Yogita Ingle 5 years, 4 months ago

When two dice are thrown, there are 36 possibilities.
However, we are given, every time both dice contain different numbers means doublet is not a possibility.
As, number of doublets are 6, so, sample space, S=36-6=30
Number of possibilities of the event when sum of dice is 4, (1,3),(3,1).
Here, we won′t take (2,2) as both dice contain different numbers.So,
E=2
So, P(E)=2/30=1/15

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ANSWER

How can we find a unit vector perpendicular to two vectors? Doesn't n cap represent a vector perpendicular to two vectors? Why can't that be used in example 23?

Posted by Kajal Gupta 5 years, 4 months ago

CBSE > Class 12 > Mathematics

2 answers

Kajal Gupta 5 years, 4 months ago

Thank you, but my doubt is n cap is also a unit vector perpendicular to both a and b vector. Then why can't we use that?

1Thank You

Shraddha ✨✰✰ 5 years, 4 months ago

Cross product of vectors A and B is perpendicular to each vector A and B. ∴ for two vectors →Aand→B if →C is the vector perpendicular to both. =(A2B3−B2A3)ˆi−(A1B3−B1A3)ˆj+(A1B2−B1A2)ˆk .

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ANSWER

MUJHE YE PUCHANA HAI KI BOARD MAI QUESTIONS TWIST KAR KAI ATA HAI YA DIRECT NCERT KA BOOK SAI DIA DIYA JATA HAI PLEASE BATA DO KOI

Posted by Adarsh Raj 5 years, 4 months ago

CBSE > Class 12 > Mathematics

4 answers

Ghanshyam Deshmukh 5 years, 4 months ago

Maths me question twist krne jaisa kuch nhi hai Basics clear hone chahiye ki question solve kaise krna hai phir toh board waale no. Bas change krte hai

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Siddhi Singh 5 years, 4 months ago

Twist

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Shraddha ✨✰✰ 5 years, 4 months ago

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Aman Kumar 5 years, 4 months ago

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CBSE > Class 12 > Mathematics

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CBSE > Class 12 > Mathematics

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CBSE > Class 12 > Mathematics

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Posted by Radhika Singhania 5 years, 4 months ago

CBSE > Class 12 > Mathematics

1 answers

Gaurav Seth 5 years, 4 months ago

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Definition	A relation is a relationship between sets of values. Or, it is a subset of the Cartesian product	A function is a relation in which there is only one output for each input.
Denotation	A relation is denoted by “R”	A function is denoted by “F” or “f”.
Example	R = {(2, x), (9, y), (2, z)} ** It is not a function, as “2” is input for both x and z.	F = {(2, x), (9, y), (5, x)}
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CBSE > Class 12 > Mathematics

2 answers

Suryakant Swain 5 years, 4 months ago

1Thank You

Shraddha ✨✰✰ 5 years, 4 months ago

x² + 3x + 2 Ans. Let y = x² + 3x + 2 .•.dy/dx = 2x + 3×1 + 0 = 2x + 3 →d²y/dx² = d/dx.(dy/dx) = 2 × 1 + 0 = 2

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CBSE > Class 12 > Mathematics

2 answers

Shraddha ✨✰✰ 5 years, 4 months ago

9999999999999999999999999999999999999999999999999999999999999999999999999.................... To +∞

0Thank You

Prem Joshi 5 years, 4 months ago

9999

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Log(1+cosx)dx

Posted by Abhishek Singh 5 years, 4 months ago

CBSE > Class 12 > Mathematics

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Palak Sharma 5 years, 4 months ago

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CBSE > Class 12 > Mathematics

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Mohsin Raza 5 years, 4 months ago

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Palak Sharma 5 years, 4 months ago

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Posted by Anil Kumar 5 years, 4 months ago

CBSE > Class 12 > Mathematics

1 answers

Gaurav Seth 5 years, 4 months ago

1. Understand the contents and weightage of the syllabus

2. Preparation from NCERT textbooks is the most important part

Though supplementary books may be used as references, the NCERT textbooks offer an exhaustive range of exercise questions and solved examples on every topic, which is more than enough to do well in your board examinations.

3. Strategize and THEN prepare!

The long form questions (5-6 marks), which are the most feared aspect of a paper, usually come from one of the following sections:

Calculus, which carries a whopping 44% weightage, and can be really scoring
Differential Equations consisting of the application based difficult questions.
Vectors and 3D geometry carry the next highest 17% weightage.

The aforementioned topics are practice-based and the best way to gain perfection in them is to practice and solve more and more problems on them. Then,

Probability, Relations and Functions and Algebra have a weightage of 10%, 10% and 13% respectively.
Linear Programming: 6%

These topics don’t require additional practice beyond the ones you have covered in your NCERT textbooks.

In linear programming, a 5-mark question comes from this chapter, which can be dealt with through little practice of understanding the questions and writing the linear equations.

4. Practice sample papers and previous years’ papers

5. Say goodbye to rote learning!

6. Presentation is very important

7. Time management

5Thank You

ANSWER

Half yearly exams me is bar kitna syllabus aane vala hai ?? Means intrigal chapter pura aayega ya half ??plz plz...plz... Koi bata do. Pls .....????

Posted by Shraddha ✨✰✰ 5 years, 4 months ago

CBSE > Class 12 > Mathematics

5 answers

Krati Varshney 5 years, 4 months ago

7.7 and 7.8 cut ho gyi h according to cbse deleted syllabus...

1Thank You

Shraddha ✨✰✰ 5 years, 4 months ago

Sab ko pahle to thanks & sorry bcz mene aap logo ko paresan kiya puch k , but me isliye puch kyuki hamare school ka syllabus R.O. pune se decide hota hai. To koi hamare pune reason ka hota to muje syllabus ka completely pata chal jata.

0Thank You

Gursimran Singh 5 years, 4 months ago

Hamare toe pura integral aa raha hai

1Thank You

Mishti ???? 5 years, 4 months ago

It is made separately by schools ... Whatever syllabus u r school is decided to give it will came in u'r exam dear...

3Thank You

Ayush Vishwakarma?? 5 years, 4 months ago

It is based on your school teacher.

4Thank You

ANSWER

Rd Sharma dekhe bhi na Kewal NCERT pde bs

Posted by Harsh Dubey 5 years, 4 months ago

CBSE > Class 12 > Mathematics

1 answers

Sweety Kadyan 5 years, 4 months ago

Yes, first give priority to NCERT and then prefer extra books .Doing NCERT two times and try to solve last year question and sample paper will help u a lot to score goodmarks in your board exam. All the best dear ..

2Thank You

ANSWER

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Posted by Harsh Dubey 5 years, 4 months ago

CBSE > Class 12 > Mathematics

1 answers

Sweety Kadyan 5 years, 4 months ago

Yes , but also try to do last year question paper that will make u ensure about Ur preparation level and u will get familiar with question paper patter

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ANSWER

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CBSE > Class 12 > Mathematics

1 answers

Divyansh Gupta 5 years, 3 months ago

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CBSE > Class 12 > Mathematics

2 answers

Dp Gour 5 years, 4 months ago

AB=I(identity fn.)

1Thank You

Ashish Kumar Tiwari 5 years, 4 months ago

AB = BA =I the relation of an inverse of a matrix is for any two matrices A & B , the inverse is only possible if AB = BA = I so it may apply conversely on your question Hope it may help

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CBSE > Class 12 > Mathematics

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CBSE > Class 12 > Mathematics

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CBSE > Class 12 > Mathematics

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CBSE > Class 12 > Mathematics

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CBSE > Class 12 > Mathematics

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Shraddha ✨✰✰ 5 years, 4 months ago

Sorry ans . adhura chhod diya. Then, dv/dx = 1/√1-(x)².d√x/dx , dv/dx =1/√1-x.1/2√x. , dv/dx = 1/2√x×√1-x. , dv/dx = 1/2√x(1-x). , dv/dx = 1/2√x-x² Then , dy/dx = du/dx + dv/dx , then dy/dx = x^sinx ×(sinx + x cosx .logx )/x + 1/2√x-x² , and first vale ans me jo dy/dx find kiya hai vo du/dx hai. Ok

0Thank You

Shraddha ✨✰✰ 5 years, 4 months ago

dy/dx = du/dx. +. dv/dx then, first we find the du/dx y = x^sinx then , y = e^sinx.logx Differ. W.r.t. x dy/dx = d/dx (e^ sinx.logx) dy/dx =e^sinx.logx .d/ dx(sinx.logx) dy/dx = x^sinx [sinx .d/dx logx + logx.d/dx sinx ] dy/dx = x^sinx (sinx + x cosx.logx )/x then , we find dv/dx dv/dx = d(sin-¹√x)/dx dv/dx = 1/√(1

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ANSWER

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Posted by Anjali Surya 5 years, 4 months ago

CBSE > Class 12 > Mathematics

1 answers

Shivam Nosaliya 5 years, 4 months ago

-3 8 -8 5

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ANSWER

the volume of cube increases at a constant rate prove that the increase in its surface varies inversely as the length of the side????????????¿?? plzz guys give me the answer

Posted by Akanksha Kumari 5 years, 4 months ago

CBSE > Class 12 > Mathematics

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Akanksha Kumari 5 years, 4 months ago

Thanks yrr

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Unnat Mishra 5 years, 4 months ago

Let the side of cube be x Volume of cube=x^3 V=x^3 Differentiating both side with respect to t dV/dt=3x^2 dx/dt = k Where k=constant dx/dt= k/3x^2 ... (1) Surface area = 6x^2 Differentiating both side dS/dt = 12x dx/dt dS/dt = 12x k/3x^2 (from 1) dS/dt = 4k/x dS/dt is directly proportional to 1/x Thus, the increase in surface area varies inversally as the length of side

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ANSWER

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Posted by Ashutosh Vishwakarma 5 years, 4 months ago

CBSE > Class 12 > Mathematics

4 answers

Arjit Arjit 5 years, 4 months ago

Here let infinite be a number and let it be £ Now infinite×infinte gives Square of infinite Which is belongs to infinite Hence our assumption is wrong infinite is not a number Thus infinite×infinite is also infinite

1Thank You

Ayush Mohite 5 years, 4 months ago

You can say infinite square but that will be once more infinite in this case since the answer infinite is greater than the product of two infinites we can get that infinite 1 (the answer) >> infinite 0 (the products)

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Arpit Namdev 5 years, 4 months ago

Its an undeterminant form

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Chandan Jaiswal 5 years, 4 months ago

You will get infinite.

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CBSE > Class 12 > Mathematics