For what value of the constant $c$ is the function $f$ continuous on $(-\infty,\infty)$ where $f(s) =\cases{s^2-c &\text{if }s\in(-\infty, 3)\\ cs+8 &\text{if } s \in [3, \infty) }$
I'm not sure what to do here....can someone tell me how to set this up? It's asking for the value of $c$. All I can think of is to set $s^2-c = cs+8$ but I don't know what $s$ is...help!!