p标签有两个类名,类名分别是color和size,下列写法正确的是?(选择一项)
查看答案
Look at the notices. Which notices (A - F) says (1-5)?
设A=B=C=R,f:A->B , g:B->C ,f(a)=a-1g(b)=b2则(g。f ) ( 2 ) =()
设A=B=C=R,f:A->B , g:B->C ,f(a)=a-1g(b)=b2则(f。g) ( 2 ) =()
设A={a,b,c,d},B={1,2,3}。确定从A到B的关系R是否是一个函数?R={(a,1),(b,2),(c,1),(d,2)}
A. 对
B. 错