Find the linear approximation to f(x, y) = 2₁ f(2.12, 8.22) f(2.12, 8.22) xy at the point (2,8, 4), and use it to approximate 4

Let f(x, y) = xty¬4. Estimate the change Af = f(4.03, 2.9) – f(4, 3) using the equation below. (Round your answer to four decimal places.) Af × fx(a, b)Ax + f,(a, b)Ay

Find the linear approximation of the function f(x, y, z) = V x2 + y2 + z² at (2, 9, 6) and use it to approximate the number 2.012 + 8.972 + 5.982. (Round your answer to five decimal places.) f(2.01, 8.97, 5.98) -

For the function f(x.y) = In (x+ 3y), find and ду dy