Let f(x,y) = 4(x^2)y + 8ln(xy)Evaluate df/dx at (x, y) = (4, 1)Evaluate df/dy at (x, y) = (4, 1). Created by Geo Cruz. science-mathematics-en - mathematics-en

δf/δx = 8xy + 8 / x ; δf/δy = 4 x² + 8 / y

calculus help? partial derivatives?

May 2021 3 53 Report

calculus help? partial derivatives?

Let f(x,y) = 4(x^2)y + 8ln(xy)

Evaluate df/dx at (x, y) = (4, 1)

Evaluate df/dy at (x, y) = (4, 1)

To get df/dx you just take the derivative as if y was a constant (which if you are doing 3-d calc this should be simple at this point)

then just plug in x=4 and y=1 to get the answer.

Same with df/dy, you treat x as a constant (derivative of 4x^2y with respect to y is just 4x^2)

âf/âx = 8xy + 8/x = 8*4*1 + 8/4 = 34 at (4, 1)

âf/ây = 4x^2 + 8/y = 8*4^2 + 8/1 = 136 at (4, 1)