Question

Find the vertex for the parabola whose equation is y= 3x^2 - 6x +5

Answer 1

The formula for finding the x value of the vertex is -b/(2a). Once you find the x value, you can plug it into the equation to find the y value.

Answer 2

I understand the process but for some reason I have had great difficulty for this problem. Would you mind going through it with me step by step? Would be much appreciated.

Answer 3

Sure. So the first step is to find the x value. The formula is -b/2a. By using this model, \[ax ^{2}+bx+c\], can you identify what "b" is?

Answer 4

in this case b is -6

Answer 5

Right, but you need b to be negative. So you will do 6/2a. In this case, a is 3. So 6/(2*3) equals what?

Answer 6

1, I thought you had to use the method of completing the square. If this works that is much better lol

Answer 7

Haha you can use this. 1 is correct. Now all you have to do is plug in 1 for x to find your y-value. :)

Answer 8

Thank you so much! Could you by any chance show me where I was going wrong when I was trying to complete the square to solve it? I started off by dividing the b value by two than squaring it. that new value replaced the c value and the previous c value was subtracted by the new c value. So I ended up with (3x^2-6x+9) - 4. from there I tried to pull out the three but thats where I ran into trouble.

Answer 9

To be honest, completing the square is not my forte. Lol, I am not the right person to ask. But I'm glad I could help!

Answer 10

Well thanks anyways!