若f[g(x)]=6x+3且g(x)=2x+1,则f(x)的解析式为 ( )
A:3
B:3x
C:32x+1
D:6x+1
It is reported that after lengthy talks the two sides finally reached a c____.
设函数fx=x+ax+b且f1=2,f2=52.
(1)求f(x)的解析式并判断函数f(x)的奇偶性;
(2)判断函数f(x)在区间(1,+∞)上单调性,并用定义法证明.