题目int_(0)^pi^2 sqrt(x) cos sqrt(x) dx = ().A. -4piB. -3piC. -2piD. -pi$\int_{0}^{\pi^2} \sqrt{x} \cos \sqrt{x} dx = ()$.A. $-4\pi$B. $-3\pi$C. $-2\pi$D. $-\pi$题目解答答案A. $-4\pi$