Change f (x) = -2(x + 1)2 + 8 into Standard Form

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.

Assume that y varies inversely with x. if y=1.6 when x=0.5 find x when y=3.2 acellus answer

How would you find the height of points on the circle? the topic is trigonometry.