$3.(25$ points$)$ Consider two firms out of a competitive industry. They have the following technologies: C$1($y$)=$ y$2+2$y; C$2($y$)=1\mathrm{.}5$y$2+3$y$.$ Show these firms$$ individual supply functions on a clearly$-$labelled graph. Con$-$ struct an aggregate supply function for these two firms on your graph.