1. The problem statement, all variables and given/known data Find the derivative of the vector function r(t)=ta X (b+at) where a=<4,5,2>, b=<1,-3,2>, and c=<4,3,1> 2. Relevant equations 3. The attempt at a solution I know how to take the derivative and everything but the way this question is worded confuses me! I'm assuming the X means cross product? but it may just mean multiply. Do I plug in the values of a,b,c, and then do what with all the t's?