Integrate: ∫ csc(x) cot(x) – sec^2(x) dx
The Correct Answer and Explanation is:
To solve the integral ∫csc(x)cot(x)−sec2(x) dx\int \csc(x) \cot(x) – \sec^2(x) \, dx∫csc(x)cot(x)−sec2(x)dx, we will break it into two simpler integrals.
Step 1: Separate the integral
We can split the integral as follows:∫csc(x)cot(x)−sec2(x) dx=∫csc(x)cot(x) dx−∫sec2(x) dx\int \csc(x) \cot(x) – \sec^2(x) \, dx = \int \csc(x) \cot(x) \, dx – \int \sec^2(x) \, dx∫csc(x)cot(x)−sec2(x)dx=∫csc(x)cot(x)dx−∫sec2(x)dx
Step 2: Solve the first integral ∫csc(x)cot(x) dx\int \csc(x) \cot(x) \, dx∫csc(x)cot(x)dx
Recall that the derivative of csc(x)\csc(x)csc(x) is −csc(x)cot(x)-\csc(x) \cot(x)−csc(x)cot(x), which is useful for recognizing the integral.
The integral of csc(x)cot(x)\csc(x) \cot(x)csc(x)cot(x) is simply −csc(x)-\csc(x)−csc(x), since:∫csc(x)cot(x) dx=−csc(x)\int \csc(x) \cot(x) \, dx = -\csc(x)∫csc(x)cot(x)dx=−csc(x)
Step 3: Solve the second integral ∫sec2(x) dx\int \sec^2(x) \, dx∫sec2(x)dx
The integral of sec2(x)\sec^2(x)sec2(x) is a standard result:∫sec2(x) dx=tan(x)\int \sec^2(x) \, dx = \tan(x)∫sec2(x)dx=tan(x)
Step 4: Combine the results
Now, we can combine the results from both integrals:∫csc(x)cot(x)−sec2(x) dx=−csc(x)−tan(x)+C\int \csc(x) \cot(x) – \sec^2(x) \, dx = -\csc(x) – \tan(x) + C∫csc(x)cot(x)−sec2(x)dx=−csc(x)−tan(x)+C
Where CCC is the constant of integration.
Final Answer:
−csc(x)−tan(x)+C-\csc(x) – \tan(x) + C−csc(x)−tan(x)+C
Explanation:
- The first integral ∫csc(x)cot(x) dx\int \csc(x) \cot(x) \, dx∫csc(x)cot(x)dx was recognized by its similarity to the derivative of csc(x)\csc(x)csc(x).
- The second integral ∫sec2(x) dx\int \sec^2(x) \, dx∫sec2(x)dx was solved using the standard formula for the derivative of tan(x)\tan(x)tan(x).
- By combining both, the result was obtained.
