# Trigonometry formulas for Class 11 and 12

## Trigonometry formulas for Class 11 and 12

Here is the list of formulas for trigonometry

• Basic Trigonometric Function Formulas
• Reciprocal Identities
• Periodicity Identities
• Cofunction Identities
• Trigonometric Identities
• Trigonometry Table
• Trigonometric function
• Trigonometry of Sum or difference in To Product
• Trigonometry of product into sum or difference
• To express trigonometric ratios of 2A in terms of trigonometric ratios of A
• Trigonometric ratios of 3A in terms of A

## Basic Trigonometric Function Formulas

• sin θ = Opposite Side/Hypotenuse
• cos θ = Adjacent Side/Hypotenuse
• tan θ = Opposite Side/Adjacent Side
• sec θ = Hypotenuse/Adjacent Side
• cosec θ = Hypotenuse/Opposite Side
• cot θ = Adjacent Side/Opposite Side

### Reciprocal Identities

The Reciprocal Identities are given as:

• cosec θ = 1/sin θ
• sec θ = 1/cos θ
• cot θ = 1/tan θ
• sin θ = 1/cosec θ
• cos θ = 1/sec θ
• tan θ = 1/cot θ

### Periodicity Identities

• sin (π/2 – A) = cos A & cos (π/2 – A) = sin A
• sin (π/2 + A) = cos A & cos (π/2 + A) = – sin A
• sin (3π/2 – A)  = – cos A & cos (3π/2 – A)  = – sin A
• sin (3π/2 + A) = – cos A & cos (3π/2 + A) = sin A
• sin (π – A) = sin A &  cos (π – A) = – cos A
• sin (π + A) = – sin A & cos (π + A) = – cos A
• sin (2π – A) = – sin A & cos (2π – A) = cos A
• sin (2π + A) = sin A & cos (2π + A) = cos A

### Cofunction Identities

• sin(90°−x) = cos x
• cos(90°−x) = sin x
• tan(90°−x) = cot x
• cot(90°−x) = tan x
• sec(90°−x) = cosec x
• cosec(90°−x) = sec x

### Trigonometric Identities

• Sin²A+Cos²A = 1

• Sin²A = 1-Cos²A

• Cos²A = 1-Sin²A

• Sec²A = 1+tan²A

• Sec²A-tan²A = 1

• Sec²A-1 = tan²A

• CoSec²A = 1+Cot²A

• CoSec²A-1 = Cot²A

• CoSec²A-Cot²A = 1

## Trigonometric function

### To Evaluate sin (A+B) formula

Sin(A+B) = SinA SinB + CosA SinB

### To Evaluate cos (A+B) formula

Cos(A+B) = CosA CosB – SinA SinB

### To Evaluate sin (A-B) formula

Sin(A-B) = SinA SinB – CosA SinB

### To Evaluate cos(A-B) formula

Cos(A-B) = CosA CosB + SinA SinB