The curves r1(t)=<t,t^2,t^3> and r2(t)=<sin t, sin 2t, t> intersect at the origin. Find their angle (acute) of interesection correct to the nearest degree. (Think! What angle are you trying to locate? Now dn't go off on a tangent.) So thats the problem. All I got so far is r1(t)=t(i)+t^2(j)+t^3(k) r2(t)=sint(i)+sin 2t(j)+t(k) Now I'm stuck. I'm not sure where to go now.