Question

how do we find directional derivative of the function f(x,y,z)=x^3y^2z^5-2xz+yz+3x

Answer 1

take the gradient of f and then dot it with unit vector in whatever direction you want to go

Answer 2

how to find the point at which the given lines intersect
r = <1,1,0> + t<1,-1,2> and r= <2,0,2> + s<-1,1,0>
and also determine the equation of the plane that contains these lines..