下列计算错误的是(）A. int_(0)^4 (dx)/(1+sqrt(x)) = int_(0)^2 (2dt)/(1+t) = 4 - 2ln 3.B. int_(0)^(pi)/(2) sin x cos x dx = int_(0)^1 sin x d(sin x)= (1)/(2).C. int_(0)^(pi)/(2) (sin x)/(5 - 3cos x) dx = int_(2)^5 (1)/(u) cdot (1)/(3) du = (1)/(3) ln (5)/(2).D. int_(1)^2 (sqrt(x^2-1))/(x) dx = int_(0)^(pi)/(3) tan t cdot sec t cdot tan t dt = sqrt(3) - (pi)/(3).

A. $\int_{0}^{4} \frac{dx}{1+\sqrt{x}} = \int_{0}^{2} \frac{2dt}{1+t} = 4 - 2\ln 3$.

B. $\int_{0}^{\frac{\pi}{2}} \sin x \cos x dx = \int_{0}^{1} \sin x d(\sin x)= \frac{1}{2}$.

C. $\int_{0}^{\frac{\pi}{2}} \frac{\sin x}{5 - 3\cos x} dx = \int_{2}^{5} \frac{1}{u} \cdot \frac{1}{3} du = \frac{1}{3} \ln \frac{5}{2}$.

D. $\int_{1}^{2} \frac{\sqrt{x^2-1}}{x} dx = \int_{0}^{\frac{\pi}{3}} \tan t \cdot \sec t \cdot \tan t dt = \sqrt{3} - \frac{\pi}{3}$.