Q. Complete the square to re-write the quadratic function in vertex form:y=x2−3x−1Answer: y=
Identify coefficients: Identify the coefficients of x2 and x in the quadratic function y=x2−3x−1. The coefficient of x2 is 1, and the coefficient of x is −3.
Find completing square value: Divide the coefficient of x by 2 and square the result to find the value to complete the square.The coefficient of x is −3, so we divide it by 2 to get −23, and then square (−23)2 to get 49.
Add/subtract completing square: Add and subtract the value found in Step 2 inside the equation to complete the square.We add and subtract 49 inside the equation to maintain the equality.y=x2−3x+49−49−1
Group and combine constants: Group the perfect square trinomial and combine the constants.y=(x2−3x+49)−49−1
Factor perfect square trinomial: Factor the perfect square trinomial.The perfect square trinomial x2−3x+49factors to (x−23)2.y=(x−23)2−49−1
Combine constants: Combine the constants to simplify the equation.We combine −49 and −1 (which is the same as −44) to get −413.y=(x−23)2−413
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