Answer: π.
- A 0
- B π
- C 2π
- D π/2
Correct answer: B. π
Explanation: ∫ x sinx dx = −x cosx + sinx. Evaluated from 0 to π this gives π.
The exact area under the curve from a to b (shaded) is approximated by a few rectangles, the Riemann sum idea behind the definite integral.