find the linear approximation of the function z = x*sqrt(y) at the point (8, 1).
L(x,y) = __________
Problems of Linear Approximation?
2013-10-18 6:11 pm
回答 (1)
2013-10-18 7:34 pm
✔ 最佳答案
f(x,y) = xy^(1/2) ==> f(8, 1) = 8.f_x(x,y) = y^(1/2) ==> f_x(8, 1) = 1.
f_y(x,y) = (1/2)xy^(-1/2) ==> f_y(8, 1) = 4.
So, L(x, y) = f(8, 1) + f_x(8, 1) (x - 8) + f_y(8, 1) (y - 1)
................= 8 + 1(x - 8) + 4(y - 1).
I hope this helps!
收錄日期: 2021-04-13 22:10:02
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20131018101100AAnU5eh