【简答题】给出下列5个命题:①函数f(x)=x|x|+ax+m是奇函数的充要条件是m=0;②若函数f(x)=lg(ax+1)的定义域是{x|x<1},则a<-1;③若log a 2<log b 2,则 lim n→∞ a n - b n a n + b n =1 (其中n∈N * );④圆:x 2 +y 2 -10x+4y-5=0上任意一点M关于直线ax-y-5a=2的对称点M'也在该圆上;⑤函数y=cos...
【简答题】下列说法中正确的命题代号为 ______. ①f(x)为奇函数,则f(0)=0; ②定义在R上的函数f(x)在区间(-∞,0]上是单调增函数,在区间[0,+∞)上也是单调增函数,则函数f(x)在R上是单调增函数; ③a,b,c都是不等于1的正数且ab≠1,则 a log c b = b log c a ; ④定义在R上的函数f(x)若f(2)≠f(-2),则函数f(x)不是偶函数.
【简答题】4 Shyness means feeling frightened when you’re around other people. Some children are 1 shy. Some become very shy later because of their life experience. 2 , everybody gets a little shy sometimes. It’...