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Ch. 4 - Applications of the Derivative
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Non è quello che usi tu?Cambia libro di testo
Capitolo 4, Problema 59b

Minimizing related functions Complete each of the following parts.
b. What value of x minimizes ƒ(x) = (x- a₁)² + (x - a₂)² + (x - a₃)² , for constants a₁, a₂, and a₃?

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First, recognize that the function ƒ(x) = (x - a₁)² + (x - a₂)² + (x - a₃)² is a sum of squares, which is a quadratic function in terms of x.
To find the value of x that minimizes this function, we need to take the derivative of ƒ(x) with respect to x. The derivative will help us find the critical points where the function could have a minimum.
Calculate the derivative: ƒ'(x) = 2(x - a₁) + 2(x - a₂) + 2(x - a₃). This simplifies to ƒ'(x) = 6x - 2(a₁ + a₂ + a₃).
Set the derivative ƒ'(x) equal to zero to find the critical points: 6x - 2(a₁ + a₂ + a₃) = 0.
Solve for x: x = (a₁ + a₂ + a₃) / 3. This value of x minimizes the function ƒ(x) because it is the point where the derivative is zero, indicating a potential minimum.

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