Q. Rewrite the function by completing the square.f(x)=x2−4x+70f(x)=(x+□)2+□
Function and Form: We start with the function f(x)=x2−4x+70 and want to rewrite it in the form f(x)=(x+□)2+□. To complete the square, we need to find a number that, when added and subtracted to the x2−4x part, completes the square.
Finding the Completing Square Number: First, we take the coefficient of the x term, which is −4, divide it by 2, and square it to find the number to complete the square. This gives us (2−4)2=(−2)2=4.
Adding and Subtracting to Complete the Square: We add and subtract this number inside the function to complete the square. We have to add 4 and subtract 4 right after the −4x term to keep the equation balanced.f(x) = x2−4x+4−4+70
Grouping the Terms: Now we group the first three terms and the last two terms separately. f(x)=(x2−4x+4)+(70−4)
Factoring the Perfect Square Trinomial: The first three terms now form a perfect square trinomial, which can be factored into (x−2)2. The last two terms combine to give 66.f(x) = (x−2)2+66
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