The curves vec$(r{)}_1(t)=($:$-2t,t^6,t^4$:$)$ and vec$(r{)}_2(t)=($:$sin(4t),sin(5t),t-$:$)$ intersect $at$ the origin.

Find the acute angle $of$ intersection $(in$ radians$)on$ the domain $0\frac{}{2},toat$ least two decimal

places.