Q. Rewrite the function by completing the square.f(x)=x2−8x−2, f(x)=(x+□)2+□
Identifying the Coefficient: We start with the function f(x)=x2−8x−2 and want to rewrite it in the form f(x)=(x+a)2+b. To complete the square, we need to find a value that, when added and subtracted to the x2−8x part, completes the square.
Completing the Square: First, we identify the coefficient of x, which is −8. To complete the square, we take half of this coefficient and square it. This gives us (2−8)2=(−4)2=16. We will add and subtract this value inside the parentheses to complete the square.
Rewriting the Function: We rewrite the function by adding and subtracting 16 inside the x terms: f(x)=(x2−8x+16)−16−2. This allows us to factor the first three terms into a perfect square.
Factoring the Perfect Square: Now we factor the perfect square: f(x)=(x−4)2−16−2. The term (x−4)2 is the completed square, and we combine the constants −16 and −2 to simplify the function.
Simplifying the Function: Combining the constants gives us f(x)=(x−4)2−18. This is the function in completed square form.
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