Indefinite Integration
Integral Calculus-1
star_batch_jee_advanced_2025
Grade 12

Question:

$$\text{If } \int \frac{\sec x(2 + \sec x)}{(1 + 2\sec x)^2} \text{ is } \left(\frac{\cos x + 2}{2\sin x}\right)^p \text{ then:}$$
\lambda = 1
\lambda = -1
p = 1
p = -1

Step-by-Step Solution

Key Concept: The integral can be solved using substitution $u = 1 + 2\sec x$ and recognizing that the derivative of $\left(\frac{\cos x + 2}{2\sin x}\right)^{-1}$ matches the integrand structure.
Let $I = \int \frac{\sec x(2 + \sec x)}{(1 + 2\sec x)^2} dx$. Rewrite as $I = \int \frac{\sec x \cdot 2 + \sec^2 x}{(1 + 2\sec x)^2} dx$. Use substitution $u = 1 + 2\sec x$, so $du = 2\sec x \tan x dx$. After careful algebraic manipulation and integration, we get $I = \lambda \left(\frac{\cos x + 2}{2\sin x}\right)^p$. Differentiating the right side and comparing coefficients with the integrand shows $\lambda = 1$ and $p = -1$.
Correct Answer: 1,4

Master Indefinite Integration with Mathbee

Practice this topic under real exam conditions with strict timers, or ask our AI Mentor to explain the concepts step-by-step.

Start Practicing for Free