00:01
For the quadratic function which is given as f of x is equal to x squared plus 2x minus 8, if we compare it with the general form we will get a equal to 1, b equal to 2 and c equal to minus 8.
00:16
Now since a is greater than 0 so it means that the parabola will definitely open upwards.
00:22
Now we need to find the vertex at hk which will be given as minus b divided by 2a and f at minus b divided by 2a.
00:32
So therefore first we'll find h which is equal to minus 2 divided by 2 multiplied with 1 which is equal to minus 1, minus 1, so f at minus 1 will be equal to minus 1 whole squared plus 2 multiplied with minus 1 minus 8 which will be equal to minus 9.
00:50
So therefore the vertex hk will be at minus 1 minus 9.
00:56
Next we need to calculate the values of x for which f of x will be 0.
01:00
So then the equation will become x squared plus 2x minus 8 is equal to 0.
01:07
That is x squared plus 4x minus 2x minus 8 is equal to 0.
01:13
That is x common x plus 4 minus 2 common x plus 4 is equal to 0...