# Facing problems in trigonometry?

• December 12th 2011, 10:40 PM
jimmiller12
Facing problems in trigonometry?
I am a high school student. I always score good marks in others subjects but find Trigonometry fairly complex. Can anyone offer tips that can help me understand trigonometry better?
• December 12th 2011, 10:52 PM
Prove It
Re: Facing problems in trigonometry?
Quote:

Originally Posted by jimmiller12
I am a high school student. I always score good marks in others subjects but find Trigonometry fairly complex. Can anyone offer tips that can help me understand trigonometry better?

I have plenty of tips, but the first thing I need to know is, what level trigonometry is this? Are you working with right-angle triangles? Non-right angle triangles? Unit Circle? Trigonometric Functions? Trigonometric Identities.
• December 12th 2011, 11:17 PM
jimmiller12
Re: Facing problems in trigonometry?
I am in level 10 trigonometry. Currently I am working on trigonometric functions and right-angle triangles.
• December 12th 2011, 11:25 PM
Prove It
Re: Facing problems in trigonometry?
Quote:

Originally Posted by jimmiller12
I am in level 10 trigonometry. Currently I am working on trigonometric functions and right-angle triangles.

Generally when dealing with right-angle triangle trigonometry...

1. Read the questions carefully. There will always be enough information there, but you might need to read it a couple of times to get all of it.

2. Draw the triangles and mark in all known lengths and angles. You always need at least two pieces of information in order to find the third. You might need to use the fact that angles in a triangle add to \displaystyle \begin{align*} 180^{\circ} \end{align*}. You might need to remember Pythagoras' Theorem. You might need to remember facts about angles formed by parallel lines cut by a traversal (e.g. X angles, F angles, Z angles).

3. There are numerous ways to remember the trigonometric ratios. "SOHCAHTOA" is the most commonly used.

Another that some of my students like is to look at the ratios like a set of three pictures...

\displaystyle \begin{align*} \sin{\theta} &= \frac{O}{H} \\ \cos{\theta} &= \frac{A}{H} \\ \tan{\theta} &= \frac{O}{A} \end{align*}

The \displaystyle \begin{align*} \frac{O}{H} \end{align*} looks like a stick figure boy, and apparently "boys sin".

The \displaystyle \begin{align*} \frac{O}{A} \end{align*} looks like a stick figure girl, and apparently "girls get tans".

As for the third, if you're asked a question, you sometimes say "Ah, Cos" :P

4. Make sure your calculator is in the correct mode.

5. Avoid rounding off any answers until the very end. The sooner you round off, the bigger the roundoff errors will be.