Math Problem Statement

Prove the identity: \( \frac{1}{1 - \sin x} + \frac{1 - \sin x}{\cos^2 x} = 2 \sec^2 x \)

Solution

To prove the trigonometric identity:

11sinx+1sinxcos2x=2sec2x\frac{1}{1 - \sin x} + \frac{1 - \sin x}{\cos^2 x} = 2 \sec^2 x

we can proceed with the following steps, as depicted in the image:

Step 1: Rewrite the Second Fraction

Rewrite the expression 1sinxcos2x\frac{1 - \sin x}{\cos^2 x} by separating terms to match the standard trigonometric identities.

Step 2: Combine the Fractions Using a Common Denominator

Find a common denominator between 11sinx\frac{1}{1 - \sin x} and 1sinxcos2x\frac{1 - \sin x}{\cos^2 x}. This common denominator will involve both (1sinx)(1 - \sin x) and cos2x\cos^2 x.

Step 3: Apply Pythagorean Identity

Use the Pythagorean identity sin2x+cos2x=1\sin^2 x + \cos^2 x = 1 to simplify expressions involving cos2x\cos^2 x in terms of sinx\sin x.

Step 4: Simplify to Show Equivalence to 2sec2x2 \sec^2 x

After combining and simplifying, aim to rewrite the expression in terms of 2sec2x2 \sec^2 x.


The image shows the steps following a structured approach, with specific algebraic and trigonometric manipulations to simplify the expression systematically.

Would you like a more detailed, step-by-step derivation of each part?

Here are 5 related questions for further exploration:

  1. How can we derive similar identities using other trigonometric functions?
  2. What are some common trigonometric identities that are helpful for proofs like this?
  3. How does this identity relate to calculus, specifically in integration?
  4. What other Pythagorean identities can be used in such trigonometric proofs?
  5. How can we verify identities graphically to understand their validity?

Tip: When working with trigonometric identities, always look for opportunities to use Pythagorean identities and express everything in terms of sine and cosine for easier simplification.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Trigonometric Identities
Pythagorean Identity
Algebraic Manipulation

Formulas

Pythagorean Identity: \( \sin^2 x + \cos^2 x = 1 \)
Secant Definition: \( \sec x = \frac{1}{\cos x} \)

Theorems

Pythagorean Identity

Suitable Grade Level

Grades 11-12