Math Problem Statement

Evaluate the integral ∫sin(5x) dx.

Solution

The integral shown in the image is:

sin(5x)dx\int \sin(5x) \, dx

Solution:

To solve this integral, we use substitution:

  1. Let u=5xu = 5x, so du=5dxdu = 5 \, dx or dx=du5dx = \frac{du}{5}.

  2. Substitute uu and dxdx into the integral: sin(5x)dx=sin(u)15du\int \sin(5x) \, dx = \int \sin(u) \cdot \frac{1}{5} \, du

  3. Take the constant 15\frac{1}{5} outside of the integral: 15sin(u)du\frac{1}{5} \int \sin(u) \, du

  4. The integral of sin(u)\sin(u) is cos(u)-\cos(u): 15(cos(u))+C=15cos(u)+C\frac{1}{5} \cdot (-\cos(u)) + C = -\frac{1}{5} \cos(u) + C

  5. Substitute back u=5xu = 5x to get the final answer: 15cos(5x)+C-\frac{1}{5} \cos(5x) + C

Final Answer:

sin(5x)dx=15cos(5x)+C\int \sin(5x) \, dx = -\frac{1}{5} \cos(5x) + C


Do you want further details or examples? Let me know!

Here are 5 related questions to explore:

  1. What is the integral of cos(5x)dx\cos(5x) \, dx?
  2. How would the solution change if the integrand was sin(ax)\sin(ax)?
  3. What is the derivative of the result 15cos(5x)+C-\frac{1}{5} \cos(5x) + C to verify the answer?
  4. How does substitution help simplify integration problems like this?
  5. How can definite integrals be applied to functions like sin(5x)\sin(5x)?

Tip: When integrating trigonometric functions with coefficients inside the argument, always consider substitution to simplify your calculations!

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Math Problem Analysis

Mathematical Concepts

Integration
Trigonometric Functions
Substitution Method

Formulas

∫sin(ax) dx = -(1/a)cos(ax) + C

Theorems

Integration by Substitution

Suitable Grade Level

Grades 10-12