Math Problem Statement

What is the exact value of sec^{-1}(2)?

Solution

The question in the image asks for the exact value of sec1(2)\sec^{-1}(2).

To solve this:

The secant function, sec(θ)\sec(\theta), is the reciprocal of the cosine function, meaning: sec(θ)=1cos(θ)\sec(\theta) = \frac{1}{\cos(\theta)}

Given sec(θ)=2\sec(\theta) = 2, we have: 1cos(θ)=2\frac{1}{\cos(\theta)} = 2

Solving for cos(θ)\cos(\theta), we get: cos(θ)=12\cos(\theta) = \frac{1}{2}

We need to find the angle θ\theta such that cos(θ)=12\cos(\theta) = \frac{1}{2}. This occurs at θ=π3\theta = \frac{\pi}{3} radians, or 60° in degrees.

Thus, the exact value of sec1(2)\sec^{-1}(2) is π3\frac{\pi}{3}.

Would you like more details on this process or have any questions?

Here are 5 related questions for further exploration:

  1. What is the relationship between secant and cosine in trigonometry?
  2. How do you find the inverse of trigonometric functions like secant and cosine?
  3. Why is the cosine of π3\frac{\pi}{3} equal to 12\frac{1}{2}?
  4. What is the domain and range of the secant function?
  5. How do you evaluate other inverse trigonometric functions such as sec1(3)\sec^{-1}(3)?

Tip: For trigonometric functions, always check for standard angles in radians and degrees to simplify calculations.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Inverse Trigonometric Functions

Formulas

sec(θ) = 1/cos(θ)
sec^{-1}(2) = cos^{-1}(1/2)

Theorems

Standard Angle Theorem for Cosine
Inverse Trigonometric Function Properties

Suitable Grade Level

Grades 10-12