这么简单都没人答.1）积分[0,a] f(x)dx = 积分[0,a/2] f(x)dx + 积分[a/2,a] f(x)dx2)设x=a-y,那么dx= - dy ,积分[a/2,a] f(x)dx = 积分[a/2,0] f(a-y) (-dy) = 积分[0,a/2] f(a-y)dy =积分[a/2,a] f(y)dy3)积分[0,a...