Question

Someone explains me, please
A: U--> V
B: V--> W
show rank (BA) \(\leq\)min{rank A, rank B}

Answer 1

I can see that rang (B) \(\supset\) range (BA) so that rank (BA) \(\leq\) rank B

Answer 2

but don't see how rank (BA) \(\leq\) rank A

Answer 3

hello, my friend. help me!!