Let c$1($t$)=$ e$^5$t i $+7$ sin$($t$)$ j $+$ t$^4$ k and c$2($t$)=$ e $^-5$t i $3$cos$($t$)$ j $-4$t$^4$k$.($Enter your soltution as a single vector using the vector form $(*,*,*).$ Use symbolic notation and fractions where needed.$)$ d$/$dt $[$c$1($t$)+$c$2($t$)]=$