00:01
So here's another tangent line problem.
00:04
And whenever you're finding the equation, you need a point and a slope.
00:08
Well, they do have to work for you by telling you the point as the ordered pair 1 -1.
00:13
What you need to do is figure out the derivative and plug in x equals 1.
00:19
So that's what we're going to do.
00:20
They give you the equation, y equals x over the square root or that function to minus x.
00:31
Squared to the one half power and you could verify if you wanted to that when you plug it one in for both of these xes you do get one and it it is true i don't want to argue over that and notice though i did change the square root to the one half power which is a true statement so let's get the quotient rule going the derivative of the top is one you leave the bottom alone to minus x squared to the one half power minus you take the derivative of the bottom, which is the chain rule, is now to the negative one half power, times the derivative of the inside, which is negative 2x, and then you leave the top alone times x all over the denominator squared.
01:21
Well, what happens when you square the square root? it goes away.
01:25
It's now to the first power, or think of a power to a power you multiply.
01:29
So this is where a lot of work needs to be done.
01:33
You have to plug in one in for all these xs...