IB Math SL Trigonometry Review - Topic 3

UPDATED VERSION OF THIS VIDEO HERE: • IB Math AA SL: Functio... . An overview of some of the basic concepts and problem types in trigonometry for the IB Math standard level course. If you want to follow along and do the problems, please download the handout at drive.google.c... . This video is neither produced by nor endorsed by the IB.

[@nadimyounes9497]

hey mathsl1 , you are a great teacher, im in a IB student and i enjoy your videos they are very resourceful. Do you think you could add some videos where you try harder problems where you really have to apply your knowledge ? cuz thats what IB is all about

[@pyro.pistol]

You are a godsend, my friend :)

[@alexm.8943]

thank you very much :) as an IB student, these videos come in handy when studying for a Topic test or just reviewing the concepts. thank you

[@udbhav27]

thank for all your videos and notes they have been really resourceful ! all your efforts are appreciated

[@kathleenm8330]

favourite review video!

[@mathsl1]

LOL!! Thanks, Kathleen!

[@rafidagamer]

Just an AMAZING review and a lot of tips, nothing else really :)

[@festivefate4045]

I have a test tomorrow and this really helped

[@lovewildpeace]

All your videos were very helpful for reviewing everything before the exam on Tuesday thank you so much! Greetings from Chile

[@adivipolak6222]

Tomorrow is my Paper 1 and those questions at the end will defo help :)

[@isaachernando9896]

Your a legend, Thank you so much for taking the time to produce such good quality math teaching videos.

[@mathsl1]

Hey leo bosca. I used the sector area formula in degrees. You will definitely see this in the context of RADIANS in the exam, so your formula in the booklet is all good. I always do the arc length and sector content before doing radians, so my students and I end up doing it in both angle measurement systems. Good luck with the exams!

[@leobosca7816]

mathsl1 Thanks for the reply.

[@9893lebron]

You are the best dude :) Thanks to you, i am going to nail the trig exam

[@alexiusyang]

THANK YOU I LEARNT MORE IN 46 MINS THAN IN A MONTH

[@e.h.6040]

man, you are great teacher, thanks for lessons.

[@jessepinkman2942]

videos are really helpful thank you

[@AayushiSrivastava3]

Hey @mathsl1 thank you so much for these videos! They've really helped! I'm a little confused by the problem at 35:25. You get an initial x value of 4pi/3 and 8pi/3 but then what do you add to get 8pi/3? I added 2pi (or 6pi/3) and ended up getting 10pi/3. Thank you! :)

[@mathsl1]

There are two initial x-values: 4pi/3 and 8pi/3. Then, in the general solution there is a "+8pi*k". This comes from a default period of 2pi, but multiplied by 4 because we started with x/4. Then we sub integer values for k to get all the solutions in the domain.x=4pi/3 + 8pi(0)=4pi/3x=8pi/3 + 8pi(0)=8pi/3x=4pi/3 + 8pi(1)=28pi/3x=8pi/3 + 8pi(1)=beyond the domain!Hope this helps.

[@mathsl1]

OMG. KZbin did publish the paragraphs so that explanation makes no sense with out them. I'll put each potential solution in a separate post. See below.

[@mathsl1]

x=4pi/3 + 8pi(0) = 4pi/3

[@mathsl1]

x=8pi/3 + 8pi(0) = 8pi/3

[@mathsl1]

x=4pi/3 + 8pi(1) = 28pi/3

[@ibstudent4366]

Ian you legend

[@FounderPilot]

i wish i had you as my teacher

[@laetaniabelaidjandam158]

thank you for existing

[@leobosca7816]

Hi, first off these videos are great, at minute 12:08 when you do the area of sector, what formula did you use, the one on the booklet is different.. Thanks for the video!

[@filmeurs.8628]

Fun fact about 38:26 - for Valentine's day I pranked my math teacher by writing a pick-up line note going like: "Wanna be the sin^2(x) to my cos^2(x)? Could lead to nice additions..." On the same day we reviewed IAs and I had to sit there for 30min one to one with him. I just wanted to bury myself in the ground and die. #mathprankbackinyourface

[@mathsl1]

Filmeurs. Lol. I think that's what Lennon was talking about in Instant Karma.

[@filmeurs.8628]

mathsl1 I think the first verse of this song was exactly written for my story haha. Thank you for all the videos btw! They are extremely helpful :)

[@duru5266]

you saved my life thank you

[@jackiecheng6386]

watching this 1.5 hrs before my finals :o

[@simonsieber5779]

THANK YOU also will you be making more?

[@patrickandreou2490]

thanks a lot this was a great help for review

[@sabrinatanumiharja6416]

thanks. I love you

[@tiffanyroyle1930]

Your videos are really helpful; but I am a little confused on when to subtract the angle from 180 in "ambiguous angles" in the triangles. Can you please explain a little more in depth? Like when would we know that we need to apply that.

[@Ballplayer300th]

Tiffany Royle he said that the calculator will always give you the acute angle. so if you're trying to find an obtuse angle you're gonna have to subtract the acute angle given by the calculator from 180 to find the obtuse angle. an example where you might need to apply that is if a problem asks you to find the angle solution, and states that it has to be greater than 90 degrees

[@mathsl1]

UPDATED VERSION OF THIS VIDEO HERE: kzbin.info/www/bejne/lXPHoYSZi6d2ipY . These videos were produced for an older version of the curriculum but they may still prove useful so I'll leave them up. You can download the blank notes using the link in the video description. I've updated the links so they should work. That said, Google is sometimes fickle with Drive access so you may have better luck accessing them in Chrome and/or signed in to a Google account.

[@marianneyang7695]

At 4:49, how did you know that tan of 30 degrees was root 3 over 3? Did you use a calculator or the unit circle, and if you used the unit circle, how did you get to that answer?

[@mathsl1]

+Marianne Yang sine over cosine. You can call tan30 1/sqrt3 or rationalize the denominator to make sqrt3/3. Same value either way. As it says on the first slide, if you've been taught differently, keep doing what you're doing.

[@marianneyang7695]

mathsl1 I got sin sqrt3/2 and cos 1/2 though

[@mathsl1]

+Marianne Yang The sine of 30 degrees is 1/2. If you have a calculator that says otherwise, it is playing a cruel, cruel practical joke on you. I suggest removing its batteries and sending it to the "timeout" chair for a few minutes.

[@marianneyang7695]

I used the hand trick, but I guess I've been doing it wrong the whole time lol

[@mathsl1]

bahaha... better to find out now!!! Good luck with the exams. I'd say your mark has just improved :-) Cheers, Ian

[@namelessnads]

Ditto \/ (obviously)

[@moozzzzz]

When you say at 33:20 that its ''periodic to 2pi''... what does that mean?

[@mathsl1]

That means solutions recur every 2pi units (or 360 degrees). Trig functions are period (ie, repeating patterns) so their general solutions reflect this.

[@shalabi569]

I don't get why we did kPi at 39:54

[@mathsl1]

It's a general solution (ie, all possible solutions) and the default period of a tangent function is pi. If you prefer, you can find both solutions in the first revolution and add 2kpi to each. It'll mean the same thing.