00:01
So this question asks me for sine x equals cosine x, what values of x is this true for? okay, so we have to think about first of all, if sine x is equal to cosine x, then sine x divided by cosine x.
00:24
Well, we have to, let me think about it this way, all right? sinx is equal to cosine x happens when x is pi over four.
00:33
Okay, we know that.
00:35
And then we have to think about the quadrants.
00:39
So sine and cosine are both positive here.
00:41
They're all positive here.
00:43
But they're not here and they're not here and they're not here.
00:46
Sign is positive here, but cosine is negative.
00:51
Okay.
00:52
Down here, cosine is negative and so is sign...