1. The problem statement, all variables and given/known data Find the directional derivative of the function given below as you arrive at (0,1,3) from the direction of (1,1,0). Give an exact answer. f(x,y,z) = sin(5 x) + ln(y^2+1) + z^3 2. Relevant equations 3. The attempt at a solution I know how to solve this if it were a 2 dimension, I am just confused on what should I multiply the k direction with? The i is multiplied with cos, the j is with sin and what about the k?