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Describe how to find what value of x must be to minimize the function f(x) = 9x^{2} - 36x + 32 using factoring.

2 Answers

5 votes

Answer: after you factor use the results (3x-6)^2 - 4 to find the minimum X value but picking a number for the X value to solve to 0.

Explanation:

Plug x=2 into the equation and it solves to 0 leave out the -4 because this is the y value

User Shane Bell
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4.1k points
4 votes

Answer: x=2, f(x)=-4

Explanation:

Given


f(x)=9x^2-36x+32

Solving it, add and subtract 4 to it


\Rightarrow f(x)=9x^2-36x+36-4\\\Rightarrow f(x)=(3x)^2+(6)^2-2* 3x* 6-4\\\Rightarrow f(x)=(3x-6)^2-4\\\\\text{here minimum value of }\ (3x-6)^2\ \text{is 0 for x=2}\\\text{so mnimum value of }\ (3x-6)^2-4\ \text{is}\ -4

User CaptEmulation
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