Definite Integration
Definite Integration
nta_abhyas_2025
Grade None

Question:

Consider $A = \int_0^{\pi/2} \frac{\sin(2x)}{1}dx$, then
A > 5/2
A < 7/2
A < 7/3
A > π/2

Step-by-Step Solution

Key Concept: Using the inequality $\sin\theta < \theta$ to establish upper bounds for integrals involving trigonometric functions
Since $\sin\theta < \theta$ for all $\theta \in (0, \frac{\pi}{2})$, we have $\sin(2x) < 2x$. Therefore $A = 2\int_0^{\pi/4} \frac{\sin(2x)}{x} dx < 2\int_0^{\pi/4} \frac{2x}{x} dx = 2\int_0^{\pi/4} 2\,dx = 2 \cdot 2 \cdot \frac{\pi}{4} = \pi$. Thus $A < 2(\frac{\pi}{2}) = \pi$.
Correct Answer: C

Master Definite 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