Evaluate (if possible) the vector-valued function at each given value of t. (If an answer does not exist, enter DNE.) r(t)= cos(t)i + 9 sin(t)j (a) r(0) i (b) r(n/4) i + (c) r(e-m)-cos(0)i-9sin (0) /3 -cos(Ar)-sin(a)-)+eir 3 cos( Ar) -sin( Ar) 2 r(n/6 +At) -r(n/6 ) (d) 2 2 2