(a) In which direction should you move if you want the concentration to increase the fastest?
(Give your answer as a vector.)
(b) You start to move in the direction you found in part (a) at a speed of cm/sec. How fast is the concentration changing?
rate of change =
2. For g(x,y)= (x^2+5y+15)^1/2, find the best linear approximation of g(x,y) for (x,y) near (1,4) .
更新1:
謝謝你的解答,自由自在 請問題1(b) 為何可以這樣計算 1. 點解partial x/partial t=v X (12/(12^2+12^2+4^2)^1/2) 2. 咁用得 partial differentiation,請問除了t之外 仲有咩係x,y,z既變量? 謝謝!