A:15
B:25
C:12
D:1
— Would you mind my using your car?— . Here is the key.
已知偶函数f(x)在R上的任一取值都有导数,且f'(1)=1f(x+2)=f(x-2)则曲线y=f(x)在x=-5处的切线的斜率为 ( )