TRG007 · Trigonometry · Classes 10–11
Secant
Secant is the reciprocal of cosine: sec θ = 1 / cos θ = hypotenuse / adjacent.
sec θSecant
📐 Formula
sec θ = 1 / cos θ
✏️ Worked example
sec 60° = 1 / 0.5 = 2.
🌍 Where it is used
Lengths of slanted beams, optics.
❓ Quick check
sec 0° = ?
🏋️ Practice
Easycos θ = 0.8. sec θ?
Answer: 1.25
MediumWhere is sec undefined between 0° and 180°?
Answer: 90°
Challengesec 45° = ?
Answer: √2