00:01
Okay, so suppose i have a point in the xy grid, and this point is negative 4, 3, negative 3.
00:08
What i could do at this point is draw a right triangle.
00:11
My x values, my x coordinates negative 4, my y values going down negative 3.
00:17
And this creates a 90 degree angle.
00:21
Suppose i want to find these trig ratios.
00:23
What are my trig ratios? well, my trig ratios are sine, cosine, and tangent.
00:28
An acronym to help remember this is soh cah toa.
00:31
Sine is opposite over hypotenuse.
00:33
Cosine is adjacent over hypotenuse.
00:35
And tangent is opposite over adjacent.
00:37
Before i do that, let's find my hypotenuse.
00:40
Great.
00:41
How do i do this? well, if i have two sides of a right triangle, solve for the third, i'm going to use the pythagorean theorem.
00:47
One side squared plus the other side squared equals the hypotenuse squared.
00:52
Negative 3 times negative 3 is positive 9.
00:55
Negative 4 times negative 4 is 16.
00:59
This will give me 25 equals c squared.
01:01
How do i get c by itself? okay.
01:04
So the opposite of square, not divide by 2, it's the square root...