1. The problem statement, all variables and given/known data The position vector of a particle at time t is given by r(t)= 2sin(2t)i + cos(2t)j + 2tk where t >=0. 2. Relevant equations v(t) = 4cos(2t)i - 2sin(2t)j + 2k speed = | v(t) | =√(16cos^2(2t)+4sin^2(2t)+4) = √(12cos^2(2t)+8) 3. The attempt at a solution I found the velocity and speed, but I have no idea what to do to find out the maximum and minimum speed for this question, someone can teach me???