[单项选择]—Would you like to see a film with us this evening —I would like to. But I can't ______ the time because I have to finish my composition. A. afford B. pass C. take D. spend
第35题: [单项选择]下列函数在(-∞,+∞)内是单调增加的函数是()。 A. f(x)=x2 B. f(x)=x4 C. f(x)=x3 D. f(x)=ex-x 参考答案:C 答案解析:由于(A)f’(x)=2x,在(0,+∞)内,f’(x)>0,故在(0,+∞)内单调增加(B)f’(x)=4x3,在(0,+∞)内,f’(x)>0,故在(0,+∞)内单调增加(C