Please help me. I am stuck with these problems. I have been working on them for entire day!

Thanks in advance very much!

This Question: 1 pt 1 of 7 (0 complete) Evaluate the following limit. lim 5e -ti - 4t 1 - 00 t+gi + tan - 1t k lim 5e -ti - 4t 1 -+ 00 - t+gi+ tan -1t k =[ (Type an exact answer, using it as needed.) Enter your answer in the answer box. Type here to search OThis Question: 1 pt 5 of 7 (0 complete) Compute the following derivative. at [ (212i + Vij - 7t- 'k) . (costi + sin 6t j- 3tk)] at [ (212) + Vij- 71-'k) . (costi + sin 6t ]-3tk)] Enter your answer in the answer box. Type here to search ma NA 9 WThis Question: 1 pt 2 of 7 (0 complete) Find the domain of the following vector-valued function. r(t) = 136-12 i + Vij + - 2 V10 +t FK Select the correct choice below and fill in any answer boxes within your choice. O A. {tits ortz} OB. {t. } O E. {t. } OH. {t. st= } Click to select and enter your answer(s). Type here to search ma N & 9 WThis Question: 1 pt 1 Berna complete)v b Compute r"(t) and r'\"(t) for the foHDwmg function, r(t) = (cos 21, sin 6L cos 4t) D rm\"): ' 1 D r\"(t)=( , Enter your answer in each ofthe answer boxes. ,0 Type hereto search