Find the directional derivative of \[f(x,y,z) = yz + x^4\] at (2,3,1) in the direction of vector v=i+j+k.
I have gotten as far as finding the directional derivative (gradient) at (2,3,1) which is:
I dont know how to do the second part of this problem. What does it mean to find this direction? What do I have to do to the gradient to find it? My book is very vague, please help!
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The box for the answer says fu= _____ , where u looks like a unit vector, is that what this is asking for? A unit vector of the gradient?
Never mind, that, I tried, and was told my answer should be a number, not a vector. Guess I misinterpreted that.