Q. Complete the square to re-write the quadratic function in vertex form:y=x2−8x+5Answer: y=
Identify Perfect Square Trinomial: To complete the square, we need to find a value that, when added and subtracted to the quadratic expression, forms a perfect square trinomial. The coefficient of x2 is 1, so we only need to focus on the x-term, which is −8x. We take half of the coefficient of x, which is −8/2=−4, and square it to get 16. This is the value we will add and subtract inside the parentheses.
Add and Subtract Value: We rewrite the quadratic function by adding and subtracting 16 inside the parentheses, and then we will move the constant term outside the parentheses.y=x2−8x+16−16+5
Group Trinomial and Constants: Now we group the perfect square trinomial and the constants separately.y=(x2−8x+16)−16+5
Factor Perfect Square Trinomial: The perfect square trinomial (x2−8x+16) can be factored into (x−4)2, and we combine the constants −16 and +5.y=(x−4)2−11
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