Trigonometry is a branch of Mathematics which deals with the measurement of the angles and the sides of a triangle, and of the various relationships existing between them. Trigonometry is introduced in Class 9 ICSE and in Class 10 CBSE. To excel in Trigonometry sums it is important to understand all the Trigonometry formulas related to Trigonometric Ratios, their various relations, Trigonometric Identities and also the Trigonometric Table.
The Brainbox Tutorials provides you with the complete list of all the formulas and identities of Trigonometry useful for classes 9 and 10. You can also download the beautiful HD quality PDF in which all the formulas have been listed comprehensively.
Basic terminology of Trigonometry
Trigonometric Ratios/ TRatios/ Trigonometric Functions
There are six Trigonometric ratios ( TRatios) sine, cosine, tangent, cosecant, secant and cotangent. Let us consider a triangle ABC rightangled at A. Let AB be its perpendicular (p), AC be its base (b) and BC be its hypotenuse, then

Reciprocal Relations between Trigonometric Ratios

Quotient Relations between Trigonometric Ratios

Trigonometric Identities



Trigonometric Table: TRatios of 0°, 30°, 45°, 60°, 90°
Trigonometric ratios of 0°, 30°, 45°, 60°, 90° are given in the following table:
Angle (ϴ)

0°

30°

45°

60°

90°

sin ϴ

0

1/2

1/√2

√3/2

1

cos ϴ

1

√3/2

1/√2

1/2

0

tan ϴ

0

1/√3

1

√3

not defined

cosec ϴ

not defined

√3

1

1/√3

0

sec ϴ

1

2/√3

√2

2

not defined

cot ϴ

not defined

√3

1

1/√3

1

Trigonometric Ratios of complementary angles
Complementary angles are the angles the sum of whose measurements is 90°. Int trigonometry, some trigonometric functions or trigonometric ratios are complementary to each other. Following is the list of Trigonometric Ratios of complementary angles.

Important links
Chapterwise Quiz/MCQ/Test:
 ICSE Chapter wise Quiz For Class 6
 ICSE Chapter wise Quiz For Class 7
 ICSE Chapter wise Quiz For Class 8
 ICSE Chapter wise Quiz For Class 9
 ICSE Chapter wise Quiz For Class 10
Sample Papers:
 Sample Papers For Class 6
 Sample Papers For Class 7
 Sample Papers For Class 8
 Sample Papers For Class 9
 Sample Papers For Class 10
Board Papers:
CBSE Related links
Chapterwise Quiz/MCQ/Test:
 CBSE Chapter wise Quiz For Class 6
 CBSE Chapter wise Quiz For Class 7
 CBSE Chapter wise Quiz For Class 8
 CBSE Chapter wise Quiz For Class 9
 CBSE Chapter wise Quiz For Class 10
Sample Papers: