Answer: -cot x + C.
- A -cot x + C
- B cot x + C
- C cosec x + C
- D -cosec x cot x + C
Correct answer: A. -cot x + C
Explanation: d/dx(-cot x) = cosec²x. So integral of cosec²x = -cot x + C.
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.