00:01
Hello, today we're going to take the derivative of a given function and evaluate it at a, and then we're going to determine the tangent line of that function as a.
00:11
So first, before taking the derivative in this type of scenario, i like to simplify the expression such that i have it in an exponential form.
00:22
So in this case, it'll be to the one -half power.
00:26
That way, when i take the derivative, i don't lose any of my parts.
00:29
So i have one -half times 2x plus 1.
00:33
And then the exponent gets attracted from 1.
00:36
So we have negative 1 half, and then we take derivative of the inside, so the derivative of 2x is 2.
00:45
So if we see that, these 2s cancel, and then that gives us 1 all over radical 2x plus 1.
00:53
That's our derivative.
00:54
Now we can evaluate this at our given point of 4, and that gives us 1 all over radical 2 times 4 plus.
01:07
So this is the same as saying one over radical nine, and square of nine is three.
01:12
So this is one over three, which equals our slope at point a in the given function.
01:22
So next, we need to take our equation of a line, y minus y -not, equals x, or sorry, n times x minus x -9...