Q. Rewrite the function by completing the square.f(x)=x2−8x−51, f(x)=(x+□)2+□
Identify Coefficients: Identify the quadratic and linear coefficients from the given quadratic function.The quadratic function is given as f(x)=x2−8x−51. Here, the quadratic coefficient is 1 (the coefficient of x2) and the linear coefficient is −8 (the coefficient of x).
Complete the Square: Divide the linear coefficient by 2 and square the result to find the number to complete the square.The linear coefficient is −8, so we divide it by 2 to get −4. Squaring −4 gives us (−4)2=16. This is the number we will add and subtract inside the parentheses to complete the square.
Rewrite the Function: Rewrite the function by adding and subtracting the number found in Step 2 inside the parentheses.We add and subtract 16 to the function f(x)=x2−8x−51 to complete the square. This gives us f(x)=(x2−8x+16)−16−51.
Factor the Quadratic Expression: Factor the quadratic expression inside the parentheses.The quadratic expression x2−8x+16 can be factored into (x−4)2 because (x−4)(x−4)=x2−8x+16.
Combine the Constants: Combine the constants outside the parentheses.We have −16−51 outside the parentheses, which combines to −67. So the function now reads f(x)=(x−4)2−67.
Final Form of the Function: Write the final form of the function after completing the square.The function after completing the square is f(x)=(x−4)2−67.
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