## Sophmoregrad2014 4 years ago how do you change standard form into vertex form

1. polpak

Typically you have to complete the square, then move the constant term to the left side with your y variable.

2. polpak

I'm assuming you're referring to the quadratic function here and not some other function with a vertex.

can you give me an example becuase its on my test tommorow and my teacher cant explain it

4. polpak

So lets say you have some quadratic equation in the form: \[y = x^2 + 2x -8\] To write it in vertex form, we need to have something like: \[y-y_1 = C(x-x_1)^2\] So we need to take the x^2 and the 2x and make something that is just (x-x1)^2. To do that, we take half of the coefficient on the x term and square that. So half of 2 is 1, 1 squared is 1. Then we simultaneously add and subtract (adding a 0) that amount out of the equation: \[\implies y = x^2 + 2x + 1 - 1\ - 8\] Then we collect out completed square: \[\implies y =(x-1)^2 - 1 -8\] Combine the constant parts: \[\implies y = (x-1)^2 - 9\] Then add or subtract the constant part to the other side: \[\implies y+9 = (x-1)^2\] That's vertex form and shows that the quadratic has a vertex at (1,-9)

5. bookymb143

change the parabola equadion from vertex form to standared form

6. bookymb143

i think that it because i suck and math