Math Problem Statement

Integrate the function (sin(x) * e^(sin(x)) - 1) / sin^2(x) with respect to x.

Solution

The expression in the image is:

sinxesinx1sin2xdx\int \frac{\sin x \cdot e^{\sin x} - 1}{\sin^2 x} \, dx

To solve this integral, we can attempt a substitution. Let's define u=sinxu = \sin x. Therefore, du=cosxdxdu = \cos x \, dx.

The integral becomes:

ueu1u2dxdudu\int \frac{u \cdot e^{u} - 1}{u^2} \cdot \frac{dx}{du} \, du

However, since dxdu\frac{dx}{du} depends on the specific relationship between xx and uu (which involves cosx\cos x), the substitution does not simplify easily without further steps.

Instead, we can simplify the integral by splitting it:

sinxesinxsin2xdx1sin2xdx\int \frac{\sin x \cdot e^{\sin x}}{\sin^2 x} \, dx - \int \frac{1}{\sin^2 x} \, dx

The second integral can be rewritten using the identity csc2x\csc^2 x (since 1sin2x=csc2x\frac{1}{\sin^2 x} = \csc^2 x):

csc2xdx=cotx\int \csc^2 x \, dx = -\cot x

For the first integral, notice that it resembles the derivative of esinxsinx\frac{-e^{\sin x}}{\sin x}. Hence, let's confirm:

ddx(esinxsinx)=sinxesinxesinxcosxsin2x=sinxesinx1sin2x\frac{d}{dx} \left(-\frac{e^{\sin x}}{\sin x}\right) = \frac{\sin x \cdot e^{\sin x} - e^{\sin x} \cdot \cos x}{\sin^2 x} = \frac{\sin x \cdot e^{\sin x} - 1}{\sin^2 x}

This shows that the first integral is:

sinxesinxsin2xdx=esinxsinx+C1\int \frac{\sin x \cdot e^{\sin x}}{\sin^2 x} \, dx = -\frac{e^{\sin x}}{\sin x} + C_1

Thus, the full solution is:

esinxsinx+cotx+C-\frac{e^{\sin x}}{\sin x} + \cot x + C

Do you want more details on any part of this solution?


Related Questions:

  1. How does the substitution method simplify complex integrals?
  2. What other methods can be used to solve similar integrals?
  3. What is the significance of trigonometric identities in solving integrals?
  4. How can we handle integrals involving exponential functions more effectively?
  5. What are some other common integrals involving csc2x\csc^2 x?

Tip: When dealing with integrals involving trigonometric functions, always look for identities or substitution methods that can simplify the expression.

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Math Problem Analysis

Mathematical Concepts

Integration
Trigonometric Functions
Exponential Functions
Integration by Parts
Substitution

Formulas

\( \int \frac{\sin x \cdot e^{\sin x} - 1}{\sin^2 x} \, dx \)
Integration by Parts: \( \int u \, dv = uv - \int v \, du \)
Trigonometric Identity: \( \csc^2 x = \frac{1}{\sin^2 x} \)

Theorems

Fundamental Theorem of Calculus
Chain Rule for Differentiation

Suitable Grade Level

Undergraduate Level