Respuesta :
					                   for example!:
f(1)=1
f(-1)=1
f(2)=2
f(-2)=2
f(-x)=x
f(x)=x
so the diagram is like the picture I send.
					                
					             f(1)=1
f(-1)=1
f(2)=2
f(-2)=2
f(-x)=x
f(x)=x
so the diagram is like the picture I send.
 
													