第1个回答 2023-07-09
这个积分需要使用分部积分法:
令 u = x, dv = sinx * dx。则 du = dx, v = -cosx。那么,该积分就等于:
=∫u * dv
= u * v - ∫v * du
= x * (-cosx)|x = π/2 → π - ∫(-cosx) * dx
= - [π * cosπ - (π/2) * cos(π/2)] + ∫cosx * dx
= - [π * (-1) - (π/2) * 0] + sinx|x = (π/2) → π
= π + [sin(π) - sin(π/2)]
= π + [0 - 1]
= π - 1
希望能够帮到你!