Get important terms and formulae of unit Trigonometric Function. This unit includes chapters: Trigonometric Functions, Trigonometric Identities and Inverse trigonometric function. This quick revision notes is very important during examination as it will help you in revising complete chapter in very short time. In some engineering entrance examinations such as UPSEE and WBJEE questions are asked directly on formula basis. This revision notes will help you to do good in the examination.

- The word ‘trigonometry’ is derived from the Greek words ‘trigon’ and ‘metron’ and it means ‘measuring the sides of a triangle’.
- Angle is a measure of rotation of a given ray about its initial point.

**Reciprocal Identities**

**Quotient Identities**

**Even/Odd Identities**

**Pythagorean Identities**

**Cofunction Identities**

**Sum and Difference Identities**

**Double-Angle Formulae**

**UPSEE 2017 Solved Sample Paper Set-1**

**Half-Angle Formulas**

**Law of Sines**

Let *a*, *b*, *c* be the sides of the triangle and *A* be the angle opposite to side *a*, *B* be the angle opposite to side *b* and *C* be the angle opposite to side *c*, then

**Law of Cosines **

Let *a*, *b*, *c* be the sides of the triangle and *A* be the angle opposite to side *a*, *B* be the angle opposite to side *b* and *C* be the angle opposite to side *c*, then

**Domain and Range of Inverse Trigonometric Function**

**JEE Main Mathematics Solved Sample Paper Set-VII**

**Important Inverse trigonometric formulae**

**JEE Main Physics Solved Sample Paper Set-VII**

**Law of Cosines**

** **

Let *a*, *b*, *c* be the sides of the triangle and *A* be the angle opposite to side *a*, *B* be the angle opposite to side *b* and *C* be the angle opposite to side *c*, then