Introduction to Trigonometry
- Basic ratio:–* sinθ = P/H (Perpendicular/Hypotenuse)
* cosθ = B/H (Base/ Hypotenuse)
* tanθ = P/B (Perpendicular/Base) - Reciprocals:–
* 1/cosecθ = 1/sinθ
* 1/secθ = 1/cosθ
* 1/cotθ = 1/tanθ - Identities:–
* sin2θ + cos2θ = 1
* 1 + tan2θ = sec2θ
* 1 + cot2θ = cosec2θ - ComplementaryAngle:–
* sin(90°– θ) = cosθ
* cos(90°- θ) = sinθ
* tanθ(90°- θ) = cotθ
* cotθ(90°- θ) = tanθ
* sec(90°- θ) = cosecθ
* cosecθ(90°- θ) = secθ