Set Theoryhard
0:00.0

For each real number t>0t > 0, we define a subset of the Cartesian plane R2\mathbb{R}^2 as follows: St={(x,y)R2:yt(x21)}S_t = \left\{ (x, y) \in \mathbb{R}^2 : y \ge t(x^2 - 1) \right\} Determine the union U=t>0StU = \bigcup_{t > 0} S_t.