\text { 8. } \mathbf{r}(t)=(\cos n) \mathbf{i}+(\sin t) \mathbf{j}+t \mathbf{k}, \quad t=0 In Exercises 7 and 8, find r, T, N, and B at the given value of r. Then

find equations for the osculating, normal, and rectifying planes at that value of t.