The directional derivative of 0 = xyz at (2,2,2) in the direction of î is (a)1 (b) 2 )3 (d) 4 o a o b oc od find the value of a, b and c, if the vector f= x+2y+

The directional derivative of 0 = xyz at (2,2,2) in the direction of î is (a)1 (b) 2 )3 (d) 4 O a O b Oc Od Find the value of a, b and c, if the vector F= x+2y+ az)i + (bx-3y-z)+ (4x + cy +2z)k is irotational (a) a = 4,b = 2,c =-1 (6) a = 4,b = 0,c =0 c) a = 2, b = 1,c =0 (d) None of these O a O b O Od