Use the Intermediate Value Theorem to show that there is a root of the given equation in the specified interval. x$4+$ x $6=0,(1,2)$ f$($x$)=$ x$4+$ x $6$ is $---$Select$---$ defined continuous negative positive on the closed interval $[1,2],$ f$(1)=,$ and f$(2)=.$ Since $4<?0<12,$ there is a number c in $(1,2)$ such that f$($c$)=?-4012$ by the Intermediate Value Theorem. Thus, there is a $---$Select$---$ root discontinuity limit of the equation x$4+$ x $6=0$ in the interval $(1,2).$