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6. [-/1 Points] DETAILS LARCALC11 12.2.028. Find the open interval(s) on which the curve given by the vector-valued function is smooth. (Enter your answer using interval notation.) r(t) = 4thi - toj Need Help? Read It 7. [-/1 Points] DETAILS LARCALC11 12.2.029. Find the open interval(s) on which the curve given by the vector-valued function is smooth. (Enter your answer using interval notation.) r(0) = 2 cos3(0) i + 4 sin3(0)j, Oses 2n Need Help? Read It Watch It 8. [-/1 Points] DETAILS LARCALC11 12.2.035. Use the properties of the derivative to find the following. r(t) = ti + 5tj + tzk, u(t) = 4ti + +2j + +3k (a) r'(t)9. [-/1 Points] DETAILS LARCALC11 12.2.039. Find the indefinite integral. (Use c for the constant of integration.) ( 2ti + j + 9k ) dt Need Help? Read It Watch It 10. [-/1 Points] DETAILS LARCALC11 12.2.050.MI. Evaluate the definite integral. TT / 4 (sec t tan t)i + (tan t)j + (2 sin t cos t)k dt Need Help? Read It Watch It Master It 11. [-/1 Points] DETAILS LARCALC11 12.2.052. Evaluate the definite integral