Which of the following relations represents a function? a. {(1, 1), (1, 2), (1, 3)} b. {(1, 1), (2, 1), (3, 1)} c. {(1, 1), (2, 2), (3, 3)} d. both b and c.

Remember ... A function relates an input to an output.It is like a machine that has an input and an output. And the output is related somehow to the input. So, I think it would be A) and C)

cells do need food. in a process known as cellular respiration, cells convert biochemical energy (oxygen as food) from nutrients into adenosine triphosphate (atp), and then release waste products.

hope this .. : d