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Ch. 3 - Polynomial and Rational Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 4, Problema 64

Among all pairs of numbers whose difference is 24, find a pair whose product is as small as possible. What is the minimum product?

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1
Let the two numbers be x and y. According to the problem, their difference is 24, so we can write the equation x - y = 24.
Express one variable in terms of the other using the difference equation. For example, x = y + 24.
Write the product of the two numbers as a function of one variable: P(y) = x � y = (y + 24) imes y = y^2 + 24y.
To find the minimum product, consider P(y) = y^2 + 24y as a quadratic function and find its vertex. Recall that the vertex of ax^2 + bx + c is at x = -\(\frac{b}{2a}\). Here, identify a and b and calculate the value of y at the vertex.
Substitute the value of y found in the previous step back into the product function P(y) to find the minimum product. Then, use x = y + 24 to find the corresponding x.

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