What is the length (magnitude) of vector (-4,2)

What is the probability of rolling a single die greater than 4

The table below shows the height of a ball  x  seconds after being kicked.  what values, rounded to the nearest whole number, complete the quadratic regression equation that models the data? f(x)  =  x2  +  x  +  0based on the regression equation and rounded to the nearest whole number, what is the estimated height after 0.25 seconds?   feet

Is this a polynomial function? i need to know asap