第2278题：反常积分和瑕点
以下反常积分计算正确的是（ ）.
A. ∫−11dxx2\int_{-1}^{1} \dfrac{dx}{x^2}∫−11x2dx =−2= -2=−2
B. ∫0tdx(1−x)2\int_0^t \dfrac{dx}{(1-x)^2} ∫0t(1−x)2dx=t1−t =\dfrac{t}{1-t}=1−tt
C. ∫1tdxt\int_1^t \dfrac{dx}{\sqrt{t}}∫1t√tdx =2t−2=2\sqrt{t}-2=2√t−2
D. ∫01xdx1−x2\int_0^1 \dfrac{xdx}{\sqrt{1-x^2}}∫01√1−x2xdx =1=1=1
