Math Problem Statement

Evaluate the integral \( \int \frac{1}{\sin^2 x \cos^2 x} \, dx \).

Solution

The integral given is:

1sin2xcos2xdx\int \frac{1}{\sin^2 x \cos^2 x} \, dx

To solve this, let's rewrite the integrand in a more manageable form.

  1. We know that sin2xcos2x\sin^2 x \cos^2 x can be rewritten using a trigonometric identity: sin2xcos2x=(sin2x2)2=sin22x4\sin^2 x \cos^2 x = \left(\frac{\sin 2x}{2}\right)^2 = \frac{\sin^2 2x}{4}

  2. Therefore, we can rewrite the integral as: 1sin2xcos2xdx=4sin22xdx\int \frac{1}{\sin^2 x \cos^2 x} \, dx = \int \frac{4}{\sin^2 2x} \, dx

  3. Since 1sin22x=csc22x\frac{1}{\sin^2 2x} = \csc^2 2x, we can rewrite this as: 4csc22xdx4 \int \csc^2 2x \, dx

  4. Now, the integral of csc2u\csc^2 u with respect to uu is cotu-\cot u. Here, let u=2xu = 2x, so du=2dxdu = 2 \, dx or dx=du2dx = \frac{du}{2}.

  5. Substitute into the integral: 4csc2udu2=2csc2udu=2(cotu)=2cot(2x)4 \int \csc^2 u \cdot \frac{du}{2} = 2 \int \csc^2 u \, du = 2(-\cot u) = -2 \cot(2x)

Thus, the solution to the integral is:

1sin2xcos2xdx=2cot(2x)+C\int \frac{1}{\sin^2 x \cos^2 x} \, dx = -2 \cot(2x) + C

Would you like further explanation on any of these steps, or have questions about related concepts?

Here are five related questions for deeper understanding:

  1. How would you integrate csc2xdx\int \csc^2 x \, dx?
  2. What is the integral of sec2x\sec^2 x and how is it different from csc2x\csc^2 x?
  3. How can trigonometric identities help simplify complex integrals?
  4. How would you solve 1sin4xdx\int \frac{1}{\sin^4 x} \, dx?
  5. What is the general method for integrating functions involving products of sine and cosine?

Tip: Using trigonometric identities can often simplify complex integrals, making them easier to evaluate.

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Math Problem Analysis

Mathematical Concepts

Trigonometric Identities
Integration
Substitution

Formulas

sin^2(x) * cos^2(x) = (sin(2x) / 2)^2
\int \csc^2(x) dx = -\cot(x) + C

Theorems

Trigonometric Integration Techniques

Suitable Grade Level

Undergraduate Calculus