I need help with this problem I don't understand ​

The deck that kenneth is building is in the shape of a parallelogram abcd the measure of angle c is one third the measure of angle b find the measure of each angle of the deck

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

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?