Stony Brook MAT 123 Fall 2015
The unit circle and trigonometry

Start   There is an easy way to remember what the sine and the cosine and the tangent are.
Draw a triangle.
And pick an angle.
Then, there are 3 sides.
There is the side opposite the angle.
So, if you are at the angle then you are looking you see the side opposite it.
The side touching the angle.
Which is the adjacent side.
We will write that out in case you forget what it stands for.
And, then you have the hypotenuse.
0:35And, yes these are both adjacent.
But, we call this adjacent and we call that hypotenuse.
And, an easy way to remember these is by a mnemonic: SOH CAH TOA.
SOH CAH TOA helps you remember what the sine, cosine, and tangent are.
And it stands for the sine of the angle is the opposite over the hypotenuse.
The cosine
1:00is the adjacent over the hypotenuse.
And the tangent is the opposite over the adjacent.
SOH CAH TOA