Which function is a quadratic function?
u(x) = –x + 3x2 – 8
v(x) = 2x2 + 8x3 + 9x
y(x) = x2 + 3x5 + 4
z(x) = 7x2 + 2x3 – 3

u(x) is a quadratic function.

Step-by-step explanation:

We are asked to choose the correct option that represents a quadratic function.

Since we know that a quadratic function is a second degree polynomial in form .

Upon looking at our given choices we can see that the function represented by option B and D are third degree polynomial, while the function represented by option C is a fifth degree polynomial, therefore, these are not correct choices.  

The polynomial represented by option A is a second degree polynomial and we can rewrite it in standard form of quadratic function as:.

Therefore, option A is the correct choice.

c

step-by-step explanation:

it isn't d, because the interquartile range is from 27-57. and the interquartile range is basically half the data, it's pretty obvious.

it isn't b, because like i said earlier, the interquartile range is from 27-57. 57-27 is 30. the real range has to be longer

not a either. although it looks like it, 3/4 of the data is not greater than 27. but if c is wrong than this should be correct

the correct answer is c, because 13 is the point in which the plot starts