题目2.当x→1时,与无穷小(1)/(2)(1-x^2)等价的是()。A. 1 - sqrt(x)B. 1 - xC. 1 - x^3D. 1 - x^42.当x→1时,与无穷小$\frac{1}{2}(1-x^{2})$等价的是()。A. $1 - \sqrt{x}$B. $1 - x$C. $1 - x^3$D. $1 - x^4$题目解答答案B. $1 - x$