00:01
We were looking for the formula for an equation, a quadratic, so we know it's a quadratic that has x intercepts at t equals negative 2 and t equals 5, and it passes through 0 .3 negative 5.
00:28
So i'm going to write the general equation.
00:33
We know y equals the a value, t and t.
00:43
So i need to figure out what numbers have to go here, so you have an x intercept at negative 2 and plus 5.
00:50
And that would be plus 2 and minus 5.
00:54
The reason why is if i rearrange this, i get t equals negative 2 and i get t equals 5.
01:01
So if i was to fill in negative 2 for this t, that makes this value 0, which makes the overall 0.
01:15
And so that makes it the y 0, which is what the y value is at your x intercept.
01:21
And if i fill in 5 here, i get 0 for this term, and 0 times anything is 0...