00:01
Okay, we want to answer these three questions of this equation.
00:06
We're not plotting its graph, just using the equation.
00:09
So i'm going to start by finding its max and min.
00:12
And to find a point, we know this is going to look something like this.
00:16
So it's a minus x square.
00:18
So more than likely, we'll be ending the maximum.
00:21
But we'll show you how to find it's max or min and how to also find the max or min.
00:28
So at the point where it is maximum or minimum, the gradient is simply going to be zero.
00:35
Okay, so to find the gradient, we just differentiate this, and where we want to find the maximum min, we just equate it to zero.
00:42
Okay? so the differentiation of minus x squared is just minus 2x.
00:47
Bring the power down, take one away.
00:49
And for the second one, bring the power down, times by one, take one away, zero.
00:53
So x is just 1, so we've got plus 14.
00:58
And we want to make this equal to zero to find our max or min.
01:01
Take two x to the side, divide by two, we should have x is equal to seven...