What is the easiest and best way to remember trigonometric ratios?
By nonew3
@nonew3 (1941)
United States
September 13, 2007 2:33pm CST
I am right now learning high-school level trigonometry on my own in preparation for taking Precalculus II (trigonometry) in college.
I am right now working on sine, cosine, and etc.
They are a bit confusing to memorize, which is adj/hyp, opp/hyp, adj/opp, opp/adj, etc.
So, what is the easiest and best way to remember trigonometric ratios?
Best answer gets a Best Response. All other good answers get a + !
Thanks for your help in this, as I am getting a bit confused.
1 person likes this
2 responses
@stvasile (7306)
• Romania
14 Sep 07
When I can't remember the definition for sin, cos, tan or ctg, I always think of this property (my math terms are not very goon in English so I'll explain it the best that I can):
In a rectangular triangle, the cathetus opposite to the 30 degree angle is half of the hypotenuse. Right?
I also know that sine (30 deg) = 1/2 so that means the definition of the sine function is (opposite cathete)/hyp.
That means that cosine = adj/hyp.
If sin=opp/hyp and cos=adj/hyp, tan, that is by deffinition sin/cos will be (opp/hyp)/(adj/hyp)= (opp/hyp)*(hyp/adj)= opp/adj.
ctan= 1/tan. If tan=opp/adj, that means that ctan=adj/opp.
I hope that helped somehow...
Another solution would be to draw the trig. circle, and see the way trig. functions are defined, but I'm guessing you didn't get so far.
1 person likes this
@nonew3 (1941)
• United States
15 Sep 07
You are talking way, WAY over my head. Huh??? What is a rectangular triangle? What is a cathetus opposite?
I am right now working through very basic high school trig before heading to the college-level version. I do know that a trig circle exists, but I know nothing about it. I have a ways to go before I get to the point that you appear to be talking about. I'm here at 2 + 2 = 4, at least in comparison to where you are.
I think I might have a look at a college trig book, although I am not quite there yet in my skill level, just so that I can see what a trig circle is for sure.
I never got as far as trigonometry in high school, and so I am having to learn it now, before I get into the college level of it.
1 person likes this
@stvasile (7306)
• Romania
15 Sep 07
Looking for the trig. circle is not a good idea at your level.
I'm sorry that I'm not very familiar with math terms in English... If I'd get them right you'll see that I'm not talking rocket science here...
For example by a "rectangular triangle" I'm simply referring to a triangle that has a 90 degree angle...
I'm sorry I couldn't be of more help.
@zhangxincow (73)
• Taiwan
20 Sep 07
Ha,this is a very difficult question.Several year I also am not early understood very much to the trigonometric function.Afterward,teacher wanted us to make the exercise,therefore I very quickly knew that did.
Therefore I thought that you made some exercises to be poddible.
Wishes you to have happy one day.
COW
