Q. Rewrite the function by completing the square.f(x)=x2+6x−78f(x)=(x+□)2+□
Identifying quadratic and linear terms: We start by identifying the quadratic and linear terms in the function f(x)=x2+6x−78 that we will use to complete the square.
Finding the perfect square trinomial: To complete the square, we need to find a number that, when added and subtracted to the quadratic and linear terms, forms a perfect square trinomial. This number is (2b)2, where b is the coefficient of the x term. In this case, b=6, so (26)2=32=9.
Adding and subtracting to create a perfect square trinomial: We add and subtract 9 to the function inside the parentheses to create a perfect square trinomial. We must also subtract 9 outside the parentheses to keep the equation balanced.f(x) = (x^2 + 6x + 9) - 9 - 78
Factoring the perfect square trinomial: Now we factor the perfect square trinomial inside the parentheses.f(x) = (x+3)2−9−78
Combining constants to simplify the function: Combine the constants outside the parentheses to simplify the function.f(x) = (x+3)2−87
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