What type of evidence is blood considered? PLEASE HELP!!

Some physical evidence is:

Explanation:

~ hair

~ fingerprints

~ blood

~soil

i am confused on the question.

to answer your question:

f(x)= a^x.  if x=0, f(x)=1  if x=1, f(x)=a  if x=1, f(x)=a^a