00:01
So for this problem, we are asked to find the axis of symmetry, vertex, and x intercepts of this quadratic that we are given.
00:07
Now, the first thing i'm going to find is the axis of symmetry by using the formula x equals negative b over 2a.
00:15
In this case, negative b would be negative 3 over 2 times negative 1 3.
00:25
So that's negative 3 over, if i multiply those together, that would be negative 2 thirds.
00:32
And when you divide by a fraction, you really multiply by the reciprocal, so i'm going to multiply by negative 3 over 2, which gives me negative, or no, positive, 9 over 2.
00:48
And that's also the x value of your vertex, which will always be the case.
00:53
The axis of symmetry and the x value of your vertex will always be the same.
00:56
So i'm going to go ahead and plot that on my graph, dotted line at 4 .5.
01:09
Okay, now to find the y value of the vertex, text, i'm going to plug 9 over 2 in for x into this function here.
01:16
So that would be negative 1 3 times 9 over 2 squared plus 3 times 9 over 2 minus 6.
01:27
I'm going to go ahead and plug that into my calculator, which gives me 3 4s.
01:53
So 9 over 2 and then 3 4s would be about right here...