1. Calculate the directional derivative of the function : (, , ) = ^2 + ^3 At the point (1, 1,1) in the direction of (3,1, 1). 2. A particle moves along the curve: =2t^2, =t^24 and =35, Where is the time. Find the components of its velocity and acceleration at time = 1, in the direction 3 + 2. 3.Show that the vector =(+3)+(3)+(2)is solenoidal. 4.Determine the constant a, b and c, so that : = ( + 2 + ) + ( 3 ) + (4 + + 2), is irrotational