Prove the function is a quadratic function

step-by-step explanation:

may i see the picture? it would a lot, xox

answer: 4  

the square root of 16 is 4. it is a very simple mathematic concept. a square root when a number multiplied by itself will result in a number. here, the number 16 comes when 4 is multiplied by 4. hence the square root of 16 is 4. you can always figure out a square root by the inverse operation of squaring.  

how many friends does he have? i think some of the information got cut off in the problem.