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Suppose that f(x, y) is a smooth function and that its partial derivatives have the values: f_x(7, 2) = -1 and f_y(7, -2) = 4. Given that f(7, -2) = 7, use this information to estimate the following values:

a)Estimate of (integer value) f(7, -1):
b)Estimate of (integer value) f(8, -2):
c)Estimate of (integer value) f(8, -1):

User Chiggins
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Final answer:

To estimate the values of f(7, -1), f(8, -2), and f(8, -1) using the given information, we can use linear approximation. The estimates are 11 for f(7, -1), 6 for f(8, -2), and 10 for f(8, -1).

Step-by-step explanation:

To estimate the values of f(7, -1), f(8, -2), and f(8, -1) using the given information, we can use the concept of linear approximation. The linear approximation formula is given by:

f(x, y) ≈ f(a, b) + f_x(a, b)(x - a) + f_y(a, b)(y - b)

where (a, b) is the given point and f_x(a, b) and f_y(a, b) are the partial derivatives at that point.

a) Estimating f(7, -1):

Using the formula, we have:

f(7, -1) ≈ f(7, -2) + f_x(7, -2)(7 - 7) + f_y(7, -2)(-1 - (-2))

f(7, -1) ≈ 7 + (-1)(0) + 4(1)

f(7, -1) ≈ 7 + 0 + 4

f(7, -1) ≈ 11

Therefore, the estimate of f(7, -1) is 11.

b) Estimating f(8, -2):

Using the formula, we have:

f(8, -2) ≈ f(7, -2) + f_x(7, -2)(8 - 7) + f_y(7, -2)(-2 - (-2))

f(8, -2) ≈ 7 + (-1)(1) + 4(0)

f(8, -2) ≈ 7 - 1 + 0

f(8, -2) ≈ 6

Therefore, the estimate of f(8, -2) is 6.

c) Estimating f(8, -1):

Using the formula, we have:

f(8, -1) ≈ f(7, -2) + f_x(7, -2)(8 - 7) + f_y(7, -2)(-1 - (-2))

f(8, -1) ≈ 7 + (-1)(1) + 4(1)

f(8, -1) ≈ 7 - 1 + 4

f(8, -1) ≈ 10

Therefore, the estimate of f(8, -1) is 10.

User Gin Quin
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