trigenometry

[zachtheterrible]

i don't know the first thing about trigenometry. i dont even know if i spelled it right!! i just got my ARRL book, and its learnin' me about impedance matching, and little did i know that i'd need a knowledge of trig to accomplish this

wut i need is to know just enuf trig to get me by . . . i no theres gotta be a good website out there that'll teach me just enuf 2 get me by :lol:

thank you

 

[vaineo]

I havn't used this site, but looking at it real quick it looks like it'll give you some of the basics. https://tutorial.math.lamar.edu/AllBrowsers/AlgebraTrigReview/AlgebraTrigIntro.asp

 

[Dr.EM]

I don't know how complex this is, but;

www.bbc.co.uk/gcsebitesize

Think thats the address^

 

[Nigel Goodwin]

I'm rather suprised?, he's 11th grade - which I presume means he's 15/16 years old - and he knows no trig?.

It's an important part of maths, and has loads of uses in everyday life, how can he not have done it at school?.

 

[checkmate]

Most of us learn it in the classrooms. As for you, I guess just grab any mathematics text. It's basically everywhere. For impedence matching, trigo is the small picture. You would need to know complex numbers in the larger context.

 

[jrz126]

I'm rather suprised?, he's 11th grade - which I presume means he's 15/16 years old - and he knows no trig?.

It's an important part of maths, and has loads of uses in everyday life, how can he not have done it at school?.

I didnt learn it until my senior year of high school, and boy was I behind when I got to college. I just took an algebra course and then I jumped to calc 1 though.

 

[Styx]

Could be the US Education system, or they changed the order.

They really should know it before the GSCE (ie by the age of 16)

I was taught it when I in the 9th year (13/14), my brother is now finishing his A-levels and he didn't learn trig until the 10th year

They might swap things around BUT it is part of our GCSE sylibus


But saying that it was only about 15years ago that calculus was on the 0-level sylibus

 

[Nigel Goodwin]

But saying that it was only about 15years ago that calculus was on the 0-level sylibus

Yes, I did calculus for O level - but more than 15 years ago :lol:

 

[bmcculla]

The basic definition of sin and cos is farily easy to understand. Think of a clock with a hour hand. Lets call 12:00 0 degrees and make the hour arm 1 foot long. At 12:00 the X-coordinate of the pointer is 0 and the Y-coordinate of the pointer is 1 foot. As the hour hand moves around clockwise the X and Y coordinates of the pointer end change - by 3:00 the X coord is 1 foot and the Y coord is 0. The sin and cos let you calculate the X and Y coordinate of the end of the pointer at each angle as it travels around. Try punching in the two known values into your calculator - for 12:00 (0 degrees): sin (0) = 0 and cos(0) = 1 for 3:00 (90 degrees) sin(90) = 1 and cos(90) = 0. At 45 degrees the sin and cos are equal.

If these values don't work your calculator probably is using Radians. Radians are just a different way to measure angle that makes the trig math a bit easier. 2pi radians = 360 degrees. So 90 degrees = 1/2 pi.

If you plot out the x-coord (sin) of the clock hand as it moves around you'll find it makes a nice sin wave. Thats why you can talk about a sin wave having an angle - its just the angle of the clock pointer at that point in its rotation.

Hope this helps.

 

[vaineo]

I never took a trig class in high school, I took a pre-cal class that had one chapter on trig and that was it.

 

[Styx]

I could sit here and type for abt 15min abt trig (not too hard)
But just read this

https://en.wikipedia.org/wiki/Trig

Also as to the Trig rule that ppl remember as SOH-CAH-TOA

I prefer

Smiles Of Happyness
Come After Having
Tankards Of Ale

sine = opposite/hypotenuse
cosine = adjacent/hypotenuse
tangent = opposite/adjacent

 

[zachtheterrible]

thanx everyone, give me a wile, im trying to digest this information . . .

none of my friends who r in 11th have had trig yet. i think america's skool systems suck. dont even get me started on the stupidity of their lagging behind, then realizing it, then PILING on the homework and PUSHING the poor kids :evil: