00:01
For this task, i would say that this is a tricky problem just because, in my experience, students struggle with trig functions.
00:09
So let me point that out real quick, that if we're concerned with the unit circle and zero, that's the order to pair one zero.
00:21
Well, sine is the y coordinate, and tangent is sine over cosine, so it's zero divided by one, which is still zero.
00:29
So if you go to direct substitute this in here, sign of zero minus zero would be equal to zero minus zero, which is still zero.
00:39
And i guess i should put an arrow there.
00:42
Same thing with tangent.
00:44
Tanger of zero minus zero is still zero minus zero, which is zero.
00:48
So we do have the lopi -tal's rule.
00:52
I like to write lh because we have the indeterminate form of zero over zero.
01:00
And so what you do is you take the same list.
01:03
Limit and you just take the derivative of the top, which is cosine, and the derivative of x is 1, and then the derivative of tangent is secund squared.
01:14
But now, cosine is 1 at x equals 0.
01:20
So now this is a little bit different...