IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: SGVaibhav on September 13, 2009, 03:48:57 pm

Title: Maths Trigonometry
Post by: SGVaibhav on September 13, 2009, 03:48:57 pm
I am learning some trigonometry now (a step further from IGCSE trigonometry) for some reasons. I came across a e book, which was good, but some part of it was very boring and made it very confusing.
I have attached the e book. The page numbers I find hard are -
47-53
62-76
Does someone have any video or something, on youtube, or any other source - illustrated or ANYTHING, that makes it easier to learn and understand this part (the boring circle  :-[)

Moderators and admins, please let this thread be here for few days and then move it later.

Thanks O0
Title: Re: Maths Trigonometry
Post by: SGVaibhav on September 13, 2009, 03:56:21 pm
lol forgot to attach the pdf file
zip file extract it.

basically i find the circle thingy hard and boring
Title: Re: Maths Trigonometry
Post by: nid404 on September 13, 2009, 04:18:16 pm
Are you confused between the circle and pi radians....If you want me to explain it i can...I'll look for videos tho
Title: Re: Maths Trigonometry
Post by: slvri on September 13, 2009, 04:21:07 pm
when i did add math i found da circle thing hard to understand as well. then i understood it using the quadrants method.
Title: Re: Maths Trigonometry
Post by: SGVaibhav on September 13, 2009, 05:39:15 pm
yeah, but i am little weak in enlish ( it takes time for me to understand things thru reading) + i am doing it by myself, so it is more harder
Title: Re: Maths Trigonometry
Post by: astarmathsandphysics on September 13, 2009, 05:56:59 pm
This is the way I teach to solve eaquations like
sinx=0.4
x=sin-10.4=23.58
Then the other solutions are

180-23.58, 360+23.58, 540-23.58, 720+23.58, 900-23.58,1080+23.58 etc

See the pattern?
cosx=0.4
x=cos-10.4=66.42
Then the other answers are

306-66.42, 360+66.42, 720-66.42, 720+66.42, 1080-66.42, 1080+66.42 etc

Again the pattern

To solve tanx=0.4
x=tan-10.4=21.80

then the other answers are180+21.8, 360+21.8, 540+21.8, 720+21.8, 900+21.8 etc
Title: Re: Maths Trigonometry
Post by: SGVaibhav on September 13, 2009, 06:25:31 pm
basically i find the circle thingy hard in the beginning itself, the radian thingy, i understood whats pi and stuff.

but i get confused with questions, such as that on page 63
question 2) 2cos(t)=..........

like i understood identities

there r few things which r hard, but the hardest thing for me is the unit circle and the items associated with it.
______

yes nid u got it what i find hard, plz try to find some nice vids
Title: Re: Maths Trigonometry
Post by: nid404 on September 14, 2009, 06:45:13 am
check this http://www.youtube.com/watch?v=9zspW8u6kQM
Title: Re: Maths Trigonometry
Post by: SGVaibhav on September 14, 2009, 09:01:08 am
hey nid, thanks for the vid, it was very good, but i understood that part.

hmmm
look at this link
http://upload.wikimedia.org/wikipedia/commons/c/c9/Unit_circle_angles.svg
its a unit circle.

i will tell what i know and what i dont :D :P

now i know the radian thingy (pi/2) and stuff
i know the degrees thingy (45deg), lol just to clarify
now those 4 lines should be the X and Y axes.
i dont know the use of (0,1) and (1,0) over here  (is it to show quadrants??)
now what is this (1/2 , (?2)/2) -- written over all angles

__________________________________
so u all know what i dont understand now (lol)
if u could explain in text, its not a prob, because i dont need a vid for this part atleast :D
_________________________________

slvri had understood this part by the quadrants method, if someone could tell that also, it would be great :D
Title: Re: Maths Trigonometry
Post by: nid404 on September 14, 2009, 09:19:52 am
okay you figured that right....the x and y coordinates tell you abt the quadrant and well the values you spoke about are also coordinates of the points on the circle(which lie in different quadrants)...

for example
for 30degrees or pi/6 radians....the coordinate for this circle(with radius 1 unit) is ( root3/2, 1/2)...which means that the x coordinate is root3/2 and y coordinate is 1/2
I hope you got it..if some1 can explain it in a better way, it would suit vaibhav
Title: Re: Maths Trigonometry
Post by: SGVaibhav on September 14, 2009, 10:49:05 am
 ??? ???
5 mins after i submitted this post, my house light went. ( i was refreshing to check if replies came)
after light came back again, i turned on my pc, i saw reply below and the light went again before i could read it
lol

yeahhhhh
thanks     :D:D:D i understood
then i tried to learn revolutions which made me go so sleepy
its boring zzzz

i feel that calculus and differentiation is way harder and INTERESTING :D
Title: Re: Maths Trigonometry
Post by: nid404 on September 14, 2009, 03:15:28 pm
Very Interesting indeed...I like it too :)
Title: Re: Maths Trigonometry
Post by: SGVaibhav on September 15, 2009, 11:11:14 am
admins u can move the thread now