Showing posts with label class10-maths. Show all posts
Showing posts with label class10-maths. Show all posts

Thursday 27 September 2018

Book For Serious Mathematics Readers - Euclid's Window: The Story of Geometry from Parallel Lines to Hyperspace

Euclid's Window: The Story of Geometry from Parallel Lines to Hyperspace

Must Read Book For Mathematics Students and Teachers
Book For Serious Mathematics Readers - Euclid's Window: The Story of Geometry from Parallel Lines to Hyperspace
Euclid's Window - Buy Ebook or Hard Copy


Through Euclid's Window Leonard Mlodinow brilliantly and delightfully leads us on a journey through five revolutions in geometry, from the Greek concept of parallel lines to the latest notions of hyperspace. Here is an altogether new, refreshing, alternative history of math revealing how simple questions anyone might ask about space in the living room or in some other galaxy have been the hidden engine of the highest achievements in science and technology.

Mlodinow reveals how geometry's first revolution began with a "little" scheme hatched by Pythagoras: the invention of a system of abstract rules that could model the universe. That modest idea was the basis of scientific civilization. But further advance was halted when the Western mind nodded off into the Dark Ages. Finally in the fourteenth century an obscure bishop in France invented the graph and heralded the next revolution: the marriage of geometry and number. Then, while intrepid mariners were sailing back and forth across the Atlantic to the New World, a fifteen-year-old genius realized that, like the earth's surface, space could be curved. Could parallel lines really meet? Could the angles of a triangle really add up to more or less than 180 degrees? The curved-space revolution reinvented both mathematics and physics; it also set the stage for a patent office clerk named Einstein to add time to the dimensions of space. His great geometric revolution ushered in the modern era of physics.

Tuesday 25 September 2018

CBSE Class 10 - Maths - Pair of Linear Equations in Two Variables - Key Points (#cbsenotes)(#eduvictors)

Pair of Linear Equations in Two Variables - Key Points

CBSE Class 10 - Maths - Pair of Linear Equations in Two Variables - Key Points (#cbsenotes)(#eduvictors)

Linear Equation

An equation which can be put in the form ax + by + c = 0, where a, b and c are real numbers and both a and b are nonzero is called a linear equation in two variables.

The solution of an Equation
Each solution (x, y) of a linear equation in two variables.

ax + by + c = 0, corresponds to a point on the line representing the equation, and vice-versa.


Pair of Linear Equations in Two Variables

The general form for a pair of linear equations in two variables x and y is
a₁x + b₁y + c₁ = 0
and a₂x + b₂y + c₂ = 0


Geometrically they look like the following:

Friday 24 August 2018

Divisibility Rules of Various Numbers - CBSE Class 6-12 - NTSE, Entrance Tests - Mathematics Tips (#cbsenotes)(#entrancetests)(#eduvictors)

Divisibility Rules of Various Numbers 

(2-25)
Divisibility Rules of Various Numbers  - CBSE Class 6-12 - NTSE, Entrance Tests - Mathematics Tips (#cbsenotes)(#entrancetests)(#eduvictors)

Divisibility by 2: 
A number is divisible by 2 if its unit’s digit is even or 0.

Divisibility by 3: 
A number is divisible by 3 if the sum of its digits are divisible by 3.

Divisibility by 4: 
A number is divisible by 4 if the last 2 digits are divisible by 4, or if the last two digits are 0’s.

Divisibility by 5: 
A number is divisible by 5 if its unit’s digit is 5 or 0.

Divisibility by 6: 
A number is divisible by 6 if it is simultaneously divisible by 2 and 3.

Wednesday 8 August 2018

CBSE Class 10 - Pair of Linear Equations In Two Variables - Solved Examples (#cbsenotes)(#eduvictors)

Pair of Linear Equations In Two Variables 
Solved Examples 

CBSE Class 10 - Pair of Linear Equations In Two Variables - Solved Examples (#cbsenotes)(#eduvictors)

☛Following questions have been asked in previous years of CBSE board examination.

Q1: Solve the following system of linear equations by elimination method (equating the coefficients).
6 (ax + by) = 3a + 2b
6 (bx – ay) = 3b – 2a

Answer:

Given equations :
6 (ax + by) = 3a + 2b ...(1)
6 (bx – ay) = 3b – 2a ...(2)

multiply eqn. (1) by a and equation (2) by b, and add, we get

6a²x + 6aby = 3a² + 2ab
6b²x – 6aby = 3b² – 2ab
────────────────────────
6 (a² + b²)x = 3(a + b)
────────────────────────

⇒ x = ½

Put x = ½ in equation (1), we have

6a × ½ + 6by = 3a + 2b

6by = 2b
y = ⅓

∴ x = ½ and y = ⅓        (Answer)

Monday 30 July 2018

CBSE Class 10 - Maths - Introduction to Trigonometry - Short Q and A (#cbsenotes)(#eduvictors)

Introduction to Trigonometry

CBSE Class 10 - Maths - Introduction to Trigonometry - Short Q and A (#cbsenotes)(#eduvictors)

Short Q and A 

Q1: If sin 3A = cos (A – 26°), where 3A is an acute angle, find the value of A.

Answer: sin 3A = cos (A – 26°)

∵ sin 3A = cos (90° – 3A)
∴ cos (90° – 3A) = cos (A – 26°)

Since
90° – 3A and A – 26° are both acute angles, therefore,
90° – 3A = A – 26°
A = 29°

Q2: Express cot 85° + cos 75° in terms of trigonometric ratios of angles between 0° and 45°.

Answer: cot 85° + cos 75° = cot (90° – 5°) + cos (90° – 15°)

= tan 5° + sin 15°


Wednesday 6 June 2018

CBSE Class 10 - Maths - Real Numbers (NCERT Exemplar Solutions Ex 1.1 Q4-6) (#cbsenotes)(#eduvictors)

Real Numbers 
(NCERT Exemplar Solutions Ex 1.1)

CBSE Class 10 - Maths - Real Numbers (NCERT Exemplar Solutions Ex 1.1 Q4-6) (#cbsenotes)(#eduvictors)

Question 4:
If the HCF of 65 and 117 is expressible in the form 65m − 117, then the value of m is
(A) 4
(B) 2
(C) 1
(D) 3

Answer: (B) 2

Explanation:
Using Euclid’s division algorithm,
b = aq + r, 0 ≤ r < a [∵ dividend = divisor × quotient + remainder]
⇒ 117 = 65 × 1 + 52
⇒ 65 = 52 × 1 + 13
⇒ 52 = 13 × 4 + 0
∴ HCF (65, 117) = 13 .... (i)

Also, given that, HCF (65, 117) = 65m – 117 ... (ii)

From Equations (i) and (ii), we get
65m − 117 = 13
⇒ 65m = 130
⇒ m = 2


Sunday 3 June 2018

CBSE Class 10 - Maths - Real Numbers (NCERT Exemplar Solutions Ex 1.1 Q1-3) (#cbsenotes)(#eduvictors)

Real Numbers (NCERT Exemplar Solutions Ex 1.1)


CBSE Class 10 - Maths - Real Numbers (NCERT Exemplar Solutions Ex 1.1 Q1-3) (#cbsenotes)(#eduvictors)


Question 1:
For some integer m, every even integer is of the form

(A) m
(B) m + 1
(C) 2m
(D) 2m + 1


Answer: (C) 2m

Explanation:
Even integers are -4, -2, 0, 2, 4, 6 ...
Let m = integers[Since, here integer is represented by m]
such that m = ⋯ , −1, 0, 1, 2, 3, ...
∴ 2m = ⋯ , −2, 0, 2, 4, 6, ...
∴ even integers can be represented in the form of 2m


Tuesday 8 May 2018

CBSE Class 9 - Lines and Angles - Brain Teaser (#cbsenotes)(#eduvictors)

Lines and Angles - Brain Teaser


Q: What is the measure of ∠A + ∠B + ∠C + ∠D + ∠E  in the figure given below, assuming no angles and sides are equal. Give reason to your answer.

CBSE Class 9 - Lines and Angles - Brain Teaser (#cbsenotes)(#eduvictors)


Answer:

Wednesday 25 April 2018

CBSE CLASS 10 - Maths - Real Numbers (NCERT Exercise 1.2) (#cbsenotes)(#eduvictors)

Real Numbers (NCERT Exercise 1.2)

CBSE CLASS 10 - Maths - Real Numbers (NCERT Exercise 1.2)  (#cbsenotes)(#eduvictors)


Q1: Express each number as product of its prime factors:
(ⅰ) 140
(ⅱ) 156
(ⅲ) 3825
(ⅳ) 5005
(ⅴ) 7429

Answer:
(ⅰ)  140 = 2 × 2 × 5 × 7 = 2 2 × 5 × 7
(ⅱ)  156 = 2 × 2 × 3 × 13 = 2 2 × 3 × 13
(ⅲ)  3825 = 3 × 3 × 5 × 5 × 17 = 3 2 × 5 2 × 17
(ⅳ)  5005 = 5 × 7 × 11 × 13
(ⅴ)  7429 = 17 × 19 × 23


Thursday 24 August 2017

Maths Pearls - What is so special about Srinivasa Ramanujan's Magic Square? (#cbseNotes)

What is so special about Srinivasa Ramanujan's Magic Square?

Maths Pearls - What is so special about Srinivasa Ramanujan's Magic Square? (#cbseNotes)


You may be familiar with magic squares. Srinivasa Ramanujan also designed his own magic square.

Maths Pearls - What is so special about Srinivasa Ramanujan's Magic Square? (#cbseNotes)


This magic square looks similar to any other square. What is so special about it?


Sum of any rows is 139

Maths Pearls - What is so special about Srinivasa Ramanujan's Magic Square? (#cbseNotes)


Tuesday 1 August 2017

CBSE Class X Mathematics - Chapter 3 - Linear equation in two variables - Revision Questions (#cbseNotes)

Chapter 3 - Linear equation in two variables - Revision Assignment 
Class X Mathematics 

CBSE Class X Mathematics - Chapter 3 - Linear equation in two variables - Revision Questions  (#cbseNotes)

1. The sum of two numbers is 6 and their difference is 4. Find the numbers


2. The sum of two numbers is 15. If the sum of their reciprocals is 3/10. Find the numbers


3. The sum of two numbers as well as the difference between their squares is 9. Find the numbers


4. If we add 5 to the denominator and subtract 5 from the numerator of a fraction, it reduces to 1/8. If we subtract 3 from the numerator and add 3 to its denominator, it reduces to 2/7. Find the fraction



Sunday 9 April 2017

CBSE Class 10 - Maths - Number Systems - Problems and Solutions (#cbsenotes)

Number Systems

Problems and Solutions
(CBSE Class 10)

CBSE Class 10 - Maths - Number Systems - Problems and Solutions (#cbsenotes)

Q1: Find HCF and LCM of 126 and 156 using prime factorization method.

Answer: HCF of 126 is:

           126
           ╱╲
          2  63
             ╱╲
            3 21
              ╱╲
             3  7

∴ 126 = 2 × 3 × 3 × 7 = 2 × 3² × 7

    HCF of 156 is:

           156
           ╱╲
          2 78
            ╱╲
           2 39
             ╱╲
            3 13

∴ 156 = 2 × 2 × 3 × 13 = 2² × 3 × 13  

∴ HCF (126, 156) = product of common factors with lowest power
= (2ⁱ × 3ⁱ) = 6