Trigonometry

Secant Calculator

Calculate the secant (sec) of an angle.

sec(θ) = 1/cos(θ) =

2

Common Angles

How to Use This Calculator

1

Enter Values

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2

Calculate

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3

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View detailed breakdowns and explanations below.

📘 Definition

Secant is the reciprocal of cosine:

sec(θ) = 1/cos(θ) = hypotenuse/adjacent

It is undefined when cos(θ) = 0 (at 90°, 270°, etc.).

🎓 Key Values

  • sec(0°) = 1
  • sec(30°) = 2/√3 ≈ 1.155
  • sec(45°) = √2 ≈ 1.414
  • sec(60°) = 2
  • sec(90°) = Undefined
  • sec(180°) = -1

💡 Properties

  • Reciprocal: sec(θ) · cos(θ) = 1
  • Periodic: sec(θ + 360°) = sec(θ)
  • Even Function: sec(-θ) = sec(θ)
  • Range: (-∞, -1] ∪ [1, ∞)
  • Derivative: d/dθ[sec(θ)] = sec(θ)tan(θ)

🚀 Applications

  • Calculus: Integration techniques
  • Physics: Optics and wave mechanics
  • Engineering: Stress analysis
  • Astronomy: Celestial calculations

⚡ Pythagorean Identity

1 + tan²(θ) = sec²(θ)

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