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Trigonometry Problem - Please help - Printable Version

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Trigonometry Problem - Please help by Shervin.B on 11-15-2005 at 08:15 AM

I had this problem in a test and I didn't know how to do it. I'm in Year 9

RE: Trigonometry Problem - Please help by Ash_ on 11-15-2005 at 08:18 AM

it's right angle trigonomotry.

this example uses Cosine (Adjacent and Hypotinuse)

so you basically put in the calculator Cos(-1) (a/3a)

understand?

RE: Trigonometry Problem - Please help by Shervin.B on 11-15-2005 at 08:19 AM

ahh yess Thankyou! I had a mind blank in the test. I hope i did well... it was our yearlies. but i don't have an A on my calculator.

RE: Trigonometry Problem - Please help by ipab on 11-15-2005 at 08:21 AM

perhaps this will aid him in remembering it better

soh cah toa

sine=opposite/hypotenuse
cosine=adjascent/hypotenuse
tangent=opposite/adjascent

hope this helps :).

the A is just a variable. It cancels out of this equation.

RE: Trigonometry Problem - Please help by John Anderton on 11-15-2005 at 09:43 AM

quote:
Originally posted by ipab
perhaps this will aid him in remembering it better

soh cah toa

sine=opposite/hypotenuse
cosine=adjascent/hypotenuse
tangent=opposite/adjascent

hope this helps [Image: msn_happy.gif].

the A is just a variable. It cancels out of this equation.
I have a better way ... well i had two but i cant remember one as i never used it ....

OAO
HHA

Sine cosine Tan

And we all know the other 3 are reciprocals of the first three ;)

Say it like "O-A-O upon (divided by) H-H-A"

Hence Sine = O/H; Cosine = A/H and Tan (Tangent) = O/A

So obviously for Cosecant, Secant and Cotangent read it the other way round (ie the bottom 3 first .....) or just remember Cosecant = 1/Sine
:D


Sin (2x) = 2 Sin (x) . Cos (x)
tanh^(-1) (x) = (1/2) * log [(1+x)/(1-x)]


</trigonometry mode>

8-) *-) :$
:P :P
RE: Trigonometry Problem - Please help by ddunk on 11-15-2005 at 03:07 PM

While we're at it, a/3a = 1/3
cos^-1(1/3) = 70.5288 = x

RE: Trigonometry Problem - Please help by Rubber Stamp on 11-15-2005 at 05:30 PM

can u calculators at school? thats cool, we cant.

RE: Trigonometry Problem - Please help by John Anderton on 11-15-2005 at 05:42 PM

quote:
Originally posted by Rubber Stamp
can u calculators at school? thats cool, we cant.
Hehe i know ..... thats why the students in our schools are good at maths (thats what i have heard)
What i have heard is that usually students from india score well in their maths sat's

I can use a calculator now that im in engineering :banana:
RE: Trigonometry Problem - Please help by user27089 on 11-15-2005 at 05:47 PM

We have always been allowed to use a calculator, only on questions that are caculator-friendly though ;).

RE: Trigonometry Problem - Please help by John Anderton on 11-15-2005 at 05:58 PM

quote:
Originally posted by traxor
We have always been allowed to use a calculator, only on questions that are caculator-friendly though ;).
The thing is that we are used to having non calculator sums (always having the angle as 0, 30, 45 or 90 .... or well .... continue that series in every quadrant) so when if we goto engineering (like i did) we have a calculator in our hands then we work faster cause we use our brains as well for the simple calculations in that series ..... but people say not to get too dependent on it .... cause then you become slower at mental mathematics cause by the end of 12th grade the best students are so good that they can tell you the answers to integration which will take 2 pages without writing a word (mental calculus) ..... pfft ..... now im lazy i do my integration on my calculator so i aint as good at mental calculus as i was then :P

quote:
Originally posted by Shervin.B
but i don't have an A on my calculator.
Which calculator are you on Shervin ??? Higher scientific calculators can directly solve 1 variable equations. For 2 and 3 variable equations there are modes .... my calculator doesnt go higher than that.
Im using a Casio fx-991MS :D
RE: Trigonometry Problem - Please help by stoshrocket on 11-15-2005 at 06:03 PM

mental calculus <shudder>... i have only just been introduced to A-level calculus as im in 5th yr doind additional maths.... i already fear my teacher...

RE: Trigonometry Problem - Please help by John Anderton on 11-15-2005 at 06:13 PM

quote:
Originally posted by Methos2
mental calculus <shudder>... i have only just been introduced to A-level calculus as im in 5th yr doind additional maths.... i already fear my teacher...
Calculus aint so tough assuming you know your trignometry :D
* John Anderton runs now :P
RE: Trigonometry Problem - Please help by Voldemort on 11-18-2005 at 09:19 PM

I love calculators

RE: Trigonometry Problem - Please help by John Anderton on 11-18-2005 at 09:23 PM

quote:
Originally posted by damm-o
I love calculators

Pfft .... i love mine too ;) But excessive use makes you kinda lazy (mentally; at mental calculus and mental calculations and stuff ie) imho :P
RE: RE: Trigonometry Problem - Please help by rav0 on 11-19-2005 at 01:19 PM

quote:
Originally posted by John Anderton
Higher scientific calculators can directly solve 1 variable equations. For 2 and 3 variable equations there are modes .... my calculator doesnt go higher than that.
Im using a Casio fx-991MS :D
You have a calculator that does algebra :o! For three variables :o!

I didn't even know that such things existed. My school sells the fx-82MS now, but they had the fx-82TL when I started high school. I have a fx-100AU.

We've all always wanted to be able to key in an equation and get an answer, and we believed that it was impossible :'(.

I guess that a calculator that can do that wouldn't be "board approved" though and we wouldn't be able to take it into our exams though.
RE: Trigonometry Problem - Please help by John Anderton on 11-19-2005 at 05:54 PM

quote:
Originally posted by rav0
You have a calculator that does algebra :o! For three variables :o!

I didn't even know that such things existed. My school sells the fx-82MS now, but they had the fx-82TL when I started high school. I have a fx-100AU.

We've all always wanted to be able to key in an equation and get an answer, and we believed that it was impossible :'(.

I guess that a calculator that can do that wouldn't be "board approved" though and we wouldn't be able to take it into our exams though.
True. It needs to be "board approved"  I could have got the fx 3000d :drool: But thats not allowed as you can store formulas (predefined functions) in it.

I have that calculator cause i aint in school anymore. And doing algebra aint a big thing here. You should know how to slove the sums with all kinds of methods .... solving it is no biggy (with the calculator, else you cant finish a 3 hour paper even in 12 hours) With a calculator like fx-100d (The "basic" scientific calculator) it will take me 4-4.5 hours to do all the calculations ....

Hence there are only a few "board approved" calculators for the year you are in. As you goto higher grades and university eventually, you'll have to upgrade your "hardware" ;)

In school you need to know how to solve stuff .... we didnt have calculators approved by our board. No state in our country can do that :P But by the time you goto university, you are already so good at it, they dont care anymore :tongue: