# Just need some formulas

1. Sep 10, 2006

### Revolver

I haven't had precalc 2 yet, so I'm not too familiar with sin, cos, tan, but I need this for my physics class.

So if you guys don't mind giving me the formulas of sin, cos, and tan.. for example: Sin angle A = width/length etc. If I have a right triangle with a hypotonuse of 7, and an angle of 35 degrees, what is the angle, and the other side.

2. Sep 10, 2006

### Math Is Hard

Staff Emeritus
A lot of people like this little device:

SOHCAHTOA
Sin = Opposite/Hypotenuse SOH
Cos = Adjacent/Hypotenuse CAH
Tan = Opposite/Adjacent TOA

3. Sep 10, 2006

### Dr Transport

SOHCAHTOA.......

sin = opposite/hypotenus

You should be able to figure it out from here....

4. Sep 10, 2006

### Dr Transport

OK MathIsHard.... we were typing at the same time and your spelling is better than mine....

5. Sep 10, 2006

### Math Is Hard

Staff Emeritus
oops, sorry, Doc!

6. Sep 10, 2006

### Dr Transport

No problem......

7. Sep 11, 2006

### Revolver

Well here's a question.. how do you know which is the opposite and which is the adjacent? Lets say you are given a triangle with sides of 4, 5 and 6, and you are required to find the angles.. how do you know which method to use?

8. Sep 11, 2006

### Kurdt

Staff Emeritus
9. Sep 12, 2006

### civil_dude

I was taught that it was 'CHIEF' SOHCAHTOA !!

10. Sep 12, 2006

### Integral

Staff Emeritus
I was taught reading down the columns

Oscar Sally
Has

A Can
Hairy

Old Tell
A

Trig functions work on Right triangles. H is the hypotenuse, that is the side opposite the right angle. The other 2 angles have an Adjacent side and an Opposite side. That is the opposite and Adjacent in the trig definitions.

11. Aug 10, 2008

### Ouabache

(i know this thread is a little dated, but still nice for reference )
I was taught "Some Old Horse Came A Hoppin' Through Our Alley" ,
using the first letters of each word will give you this

sin = Some Old Horse (sin = opposite/hypotenuse)
cos = Came A Hoppin' (cos = adjacent/hypotenuse)
tan = Through Our Alley (tan = opposite/adjacent)

Last edited by a moderator: Aug 11, 2008