Math Problem Statement

Solve 1/(secx-1)+1/(secx+1)

Solution

To solve the expression:

1sec(x)1+1sec(x)+1\frac{1}{\sec(x) - 1} + \frac{1}{\sec(x) + 1}

We can follow these steps:

Step 1: Combine the fractions

We first combine the two terms into a single fraction. To do that, we find a common denominator. The common denominator between sec(x)1\sec(x) - 1 and sec(x)+1\sec(x) + 1 is:

(sec(x)1)(sec(x)+1)(\sec(x) - 1)(\sec(x) + 1)

Now, using this common denominator, we can rewrite the expression as:

1sec(x)1+1sec(x)+1=(sec(x)+1)+(sec(x)1)(sec(x)1)(sec(x)+1)\frac{1}{\sec(x) - 1} + \frac{1}{\sec(x) + 1} = \frac{(\sec(x) + 1) + (\sec(x) - 1)}{(\sec(x) - 1)(\sec(x) + 1)}

Step 2: Simplify the numerator

Simplify the numerator:

(sec(x)+1)+(sec(x)1)=sec(x)+1+sec(x)1=2sec(x)(\sec(x) + 1) + (\sec(x) - 1) = \sec(x) + 1 + \sec(x) - 1 = 2\sec(x)

Step 3: Simplify the denominator

The denominator is a difference of squares:

(sec(x)1)(sec(x)+1)=sec2(x)1(\sec(x) - 1)(\sec(x) + 1) = \sec^2(x) - 1

We can use the Pythagorean identity sec2(x)1=tan2(x)\sec^2(x) - 1 = \tan^2(x). Therefore, the denominator simplifies to tan2(x)\tan^2(x).

Step 4: Final expression

Now we can rewrite the whole expression as:

2sec(x)tan2(x)\frac{2\sec(x)}{\tan^2(x)}

Step 5: Further simplification

We know that sec(x)=1cos(x)\sec(x) = \frac{1}{\cos(x)} and tan(x)=sin(x)cos(x)\tan(x) = \frac{\sin(x)}{\cos(x)}. Thus:

2sec(x)tan2(x)=2cos(x)cos2(x)sin2(x)=2cos(x)sin2(x)\frac{2\sec(x)}{\tan^2(x)} = \frac{2}{\cos(x)} \cdot \frac{\cos^2(x)}{\sin^2(x)} = \frac{2\cos(x)}{\sin^2(x)}

This is the simplified form of the expression.

Final Answer:

2cos(x)sin2(x)\frac{2\cos(x)}{\sin^2(x)}

Would you like further details or have any questions?


Here are 5 related questions for further practice:

  1. Simplify 1sec(x)2+1sec(x)+2\frac{1}{\sec(x)-2} + \frac{1}{\sec(x)+2}.
  2. Prove the identity: sec2(x)tan2(x)=1\sec^2(x) - \tan^2(x) = 1.
  3. Simplify 11sin(x)+11+sin(x)\frac{1}{1 - \sin(x)} + \frac{1}{1 + \sin(x)}.
  4. Solve sin(x)1+cos(x)+sin(x)1cos(x)\frac{\sin(x)}{1 + \cos(x)} + \frac{\sin(x)}{1 - \cos(x)}.
  5. Simplify 1tan(x)+1+1tan(x)1\frac{1}{\tan(x) + 1} + \frac{1}{\tan(x) - 1}.

Tip:

When simplifying trigonometric expressions, always check if any Pythagorean identities can help reduce the complexity.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Simplification of Trigonometric Expressions
Pythagorean Identity

Formulas

sec(x) = 1/cos(x)
tan(x) = sin(x)/cos(x)
sec^2(x) - 1 = tan^2(x)

Theorems

Pythagorean Identity
Difference of Squares

Suitable Grade Level

Grades 11-12