Showing posts with label Trigonometry. Show all posts
Showing posts with label Trigonometry. Show all posts

Friday, December 22, 2017

CBSE Class XI - chap. I-3. Trigonometric Functions - Learning Companion



3. Trigonometric Functions

Positive and negative angles. Measuring angles in radians and in degrees and conversion of one into other.

Definition of trigonometric functions with the help of unit circle. Truth of the sin2x+cos2x=1, for all x.  Signs of trigonometric functions. Domain and range of trignometric functions and their graphs. Expressing sin (x±y) and cos (x±y) in terms of sinx, siny, cosx & cosy and their simple application. Deducing identities like the following:

Identities related to sin 2x, cos 2x, tan 2x, sin 3x, cos 3x and tan 3x. General solution of trigonometric equations of the type sin y = sin a, cos y = cos a and tan y = tan a.


Maths Trigonometry part 1 (Basic Concepts, Why Trigonometry) CBSE class 11 Mathematics XI
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ExamFear Education


Maths Trigonometry part 2 (Degree Measure) CBSE class 11 Mathematics XI
https://www.youtube.com/watch?v=1FijJ6tuqW4

Maths Trigonometry part 3 (Radian Measure) CBSE class 11 Mathematics XI
https://www.youtube.com/watch?v=Bleq2RyPFUE


Wednesday, December 24, 2014

33. Trigonometric ratios, Identities and Maximum & Minimum Values of Trigonometrical Expressions - Revision Facilitator

Sections in the chapter


33.1 Introduction
33.2 Some basic formulae
33.3 Domain and range of trigonometrical functions
33.4 Sum and difference formulae
33.5 Sum and difference into products
33.6 Product into sum or difference
33.7 T-ratios of the sum of three or more angles
33.8 Values of trigonometrical ratios some important angles and some important results.
33.9 Expressions of sin A/2 and cos A/2 in terms of sin A.
33.10 Maximum and minimum values of trigonometrical functions

Study Plan


Day 1

33.1 to 33.4

33.1 Introduction
33.2 Some basic formulae
33.3 Doman and range of trigonometrical functions
33.4 Sum and difference formulae

Do objective type exercises 58,

Day 2

33.5 Sun and difference into products
33.6 product into sum and difference

Do objective type exercises 84,91, 92, 104, 115,

Day 3

33.7 T-ratios of the sum of three or more angles

Do objective type exercises 39, 44, 106, 113, 117,

Day 4

33.8 Values of trigonometric ratios of some important angles and some important results

Do objective type exercises 1,2,3,5,6,7,8,9,10,11

Day 5

33.9 Expressions of sin A/2 and cos A/2 in terms of sin A

Do objective type exercises 12,13,14,15,16,17,19,20,21,22

Day 6

33.10 maximum and minimum values of trigonometrical functions

O.T.E.: 4,18,23-30

Day 7

O.T.E.: 31 to 50

Day 8

O.T.E.: 51 to 70

Day 9
O.T.E.: 71 to 90



Day 10
O.T.E.: 91 to 110

Revision Period

Day 11
O.T.E.: 111 to 120



Day 12
O.T.E.: 121 to 130


Day 13
O.T.E.: 131 to 140


Day 14
O.T.E.: 141 to 148


Day 15
Fill in the blanks type exercise: 1 to 10


Day 16
Fill in the blanks type exercise: 11 to 20


Day 17
Fill in the blanks type exercise: 21 to 30


Day 18
Fill in the blanks type exercise: 31 to 36


Day 19
True/false type exercise: 1 to 12


Day 20
Fill in the blanks type exercise: 13 to 25

Day 21
Practice Exercise: 1 to 10

Day 22
Practice Exercise: 11 to 20

Day 23
Practice Exercise: 21 to 32

Day 24
Formula Revision

Day 25
Formula Revision





Revision facilitator


33.1 Introduction
33.2 Some basic formulae
33.3 Domain and range of trigonometrical functions
33.4 Sum and difference formulae
33.5 Sum and difference into products
33.6 Product into sum or difference
33.7 T-ratios of the sum of three or more angles
33.8 Values of trigonometrical ratios some important angles and some important results.
33.9 Expressions of sin A/2 and cos A/2 in terms of sin A.
33.10 Maximum and minimum values of trigonometrical functions

Tuesday, May 20, 2008

Revision Material Ch 33. Trigonometric Ratios - 1

I.
Function-------------Domain--------------Range

Sin θ------------------R----------------[-1,1]

cos θ------------------R-----------------[-1,1]

tan θ------------R-{(2n+1)π/2, nЄI}------R=(-∞. ∞)




II.Basic relations

sin θ*cosec θ = 1

cos θ*sec θ = 1

tan θ*cot θ = 1

sin² θ + cos² θ = 1

sec²θ - tan²θ =1; 1 + tan² θ = sec² θ

cosec²θ - cot²θ = 1; 1+cot2θ = cosec²θ


III. Allied or Related angles

1. sin (-θ) = -sin θ
2. cos(-θ) = cos θ



IV.Compound angles

1. sin (A+B) = sin A cos B + cosA sin B

2. sin 2A = 2 sin A cos A

3. sin (A-B) = sin A cos B - cos A sin B

4. cos (A+B) = cos A cos B -sin A sin B

5 cos 2A = cos²A - sin²A

6. cos (A-B) = cos A cos B + sin A sin B

Revision Material Ch 33. Trigonometric Ratios - 2

sin (A+B+C) = sin A cos B cos C + sin B cos A cos C + sin C cos A cos B - sin A sin B sin C

sin 3A = 3 sin A - 4 sin³A

Cos (A+B+C) = cos A cos B cos C - cos A sin B sin C - Cos B sin A sin C - cos C sin A sin B


tan (A+B+C) = [tan A + tan B + tan C - tan A tan B tan C]/[ 1- tan A tan B - tan B tan C - tan C tan A]

Transformation Formulae

sin (A+B) + sin (A-B) = 2 sin A cos B

2 sin A cos B = sin (A+B) + sin (A-B)

sin (A+B) - sin (A-B) = 2cos A sin B

2cos A sin B = sin (A+B) - sin (A-B)

cos (A+B) + cos (A-B) = 2cos A cos B

2cos A cos B = cos (A+B) + cos (A-B)

cos (A+B) - cos (A-B) = 2sin A sin B

2sin A sin B = cos (A+B) - cos (A-B)

Therefore

2 sin A cos B = sin (A+B) + sin (A-B)
2cos A sin B = sin (A+B) - sin (A-B)
2cos A cos B = cos (A+B) + cos (A-B)
2sin A sin B = cos (A+B) - cos (A-B)

The products of two sines or two cosines and one sine and one cosine can be transformed into the sum or differences of two sines or two cosines.




Trigonometric ratios of multiple angles

Trigonometric ratios of angle 2A in terms of an angle A

Sin 2A = 2sin A cos A
Sin 2 A = 2tan A/(1 + tan² A)

Cos 2A = cos² A - sin² A
Cos 2A = 2cos² A – 1
Cos 2A = 1 – 2sin² A
cos 2A = (1- tan² A)/(1+ tan² A)

tan 2A = 2tan A/(1 - tan² A)


Trigonometric ratios of angle 3A in terms of an angle A

Sin 3A = 3sin A - sin³ A

cos 3A = 4cos³ A – 3cos A

tan 3A = (3tan A - tan³ A)/(1-3tan² A)

Trigonometric ratios of sub-multiple angles

Trigonometric ratios of angle A in terms of an angle A/2

sin A = 2sin A/2 cos A/2
sin A = (2tan A/2)/(1 + tan² A/2)

cos A = cos² A/2 - sin² A/2
cos A = 2cos² A/2 – 1
cos A = 1 – 2sin² A/2
cos A = (1- tan² A/2)/(1+ tan² A/2)

tan A = (2tan A/2)/(1 - tan² A/2)


Trigonometric ratios of angle A in terms of an angle A/3

Sin A = 3sin (A/3) - sin³ (A/3)

cos A = 4cos³ (A/3) – 3cos (A/3)

tan A = (3tan (A/3) - tan³ (A/3))/(1-3tan² (A/3))

Trigonometric ratios of angle A/2 in terms of an angle cos A

cos A/2 = ±√[(1+cos A)/2]

sin A/2 = ±√[(1-cos A)/2]

tan A/2 = ±√[(1-cos A)/(1 + cos a)]

Monday, October 22, 2007

STUDY GUIDE CH.11 ELEMENTARY TRIGONOMETRY

JEE SYLLABUS

Trigonometric functions, their periodicity and graphs, addition and subtraction formulae, formulae involving multiple and sub-multiple angles,
-----------------------

CH. 12. APPLICATION OF TRIGONOMETRY, TRIANGLES

JEE SYLLABUS

Relations between sides and angles of a triangle, sine rule, cosine rule, half-angle formula and the area of a triangle,
-------------------

Study Guide Ch. 13. TRIGONOMETRIC EQUATIONS

JEE SYLLABUS

general solution of trigonometric equations.

-------------------------
JEE Question

Let F(x) be an indefinite integral of sin^2 x.

Statement - 1

The function F(x) satisfies F(x +Pi) = F(x) for all real x.

Because

Statement - 2

sin^2 (x+ Pi) = sin^2 x for all real x.

(A) Statement – 1 is True, Statement – 2 is True; Statement – 2 is a correct explanation for statement – 1
(B) Statement – 1 is True, Statement – 2 is True; Statement – 2 is Not a correct explanation for Statement – 1.
(C) Statement – 1 is True, Statement – 2 is False
(D) Statement – 1 is False, Statement – 2 is True

answer D
--------------------
JEE 2007 Paper I

The number of solutions of the pair of equations
2sin²θ - cos2θ = 0
2cos²θ - 3sinθ = 0
in the interval [0,2π] is

(A) zero
(B) one
(C) two
(D) four

Answer: C
-----------------------

CH. 14 INVERSE OF TRIGONOMETRIC FUNCTIONS

JEE SYLLABUS

inverse trigonometric functions (principal value only).
---------------------

JEE 2007 Paper II

Let (x,y) be such that Sin‾¹(ax) + Cos‾¹(y)+Cos‾¹(bxy) = π/2
Match the statements in Column I with statements in Column II and indicate your answer by darkening the appropriate bubbles in the 4 × 4 matrix given in the ORS.


Column I --------------------- Column II
(A) If a = 1 and b = 0,------(p) lies on the circle
then (x, y)----------------- x² + y² = 1
===================================================
(B) If a = 1 and b = 1, ----(q) lies on
then (x, y)----------------- ( x²-1)(y²-1) =0
===================================================
(C) If a = 1 and b = 2,-----(r) lies on y = x
then (x, y)
===================================================


(D) If a = 2 and b = 2,-----(s) lies on
then (x, y)------------------ (4x²-1)(y²-1) = 0 ===================================================
Solution

(A) : (p)
(B) : (q)
(C) : (p)
(D) : (s)
-----------------------------------