Trigonometric Functions - I

An angle is formed by rotating

An angle is formed by rotating a ray from its initial position. When the rotation is counterclockwise, the angle is positive; when clockwise, it is ne

A degree (°) measures an angle

A degree (°) measures an angle by dividing a complete rotation into 360 equal parts. A radian is the angle subtended at the center of a circle by an a

When an angle θ (in radians)

When an angle θ (in radians) is subtended at the center of a circle with radius r, the corresponding arc length is ℓ = rθ. This formula connects three

A unit circle (radius = 1)

A unit circle (radius = 1) centered at the origin provides the geometric foundation for defining trigonometric functions. For any angle θ measured cou

Since (x

Since (x, y) coordinates on the unit circle satisfy x² + y² = 1, we have -1 ≤ cos θ ≤ 1 and -1 ≤ sin θ ≤ 1. The domain of sin and cos is all real numb