MG Week 1

Trigonometry

Trigonometric Ratios

The 4 Quadrants

Simple Trigonometric Functions & Identities

Basic Trigonometric Identities

sin² θ + cos² θ = 1

1 + tan² θ = sec² θ

1 + cot² θ = cosec² θ

Double Angle Formula

sin 2A = 2 sin A cos A

cos 2A = cos² A - sin² A
   = 2 cos² A - 1
   = 1 - 2 sin² A

Compound Angle Formula

sin (A ± B) = sin A cos B ± cos A sin B

cos (A ± B) = cos A cos B ∓ sin A sin B

R Method

a sin θ ± b cos θ = R sin(θ ± α)

a cos θ ± b sin θ = R cos(θ ∓ α)

Where,

R = √(a² + b²)

fin