There are literally NO flaws in his methods of teaching. If I had to give a flaw it would be for the the bad resolution on the old videos. But he now has HD versions, so in short, he's a beast!
The hypotenuse is 1 because of the unit circle (I don't know how else to put it). Just refer back to your unit circle and you will see that the radius is 1, which is also the hypotenuse. Keep in mind, that is ONLY on the unit circle. "o" is just opposite, as in, side opposite of the angle (in this case V)
ur awesome man. u dont know how many people uve helped nail this subject. im learning right now. i have a test in a few days and thanks to you im going to pass :) god bless
Thank you very much for that useful information explaining the maths behind trigonometric identities. As a year 10 student it has really helped me get a grasp on some A level maths.
Around 1:20 you seem confused about why there is a secant and cosecant. The reason for that is because raising sine and cosine to the negative first power (sin^-1 or cos^-1), which would normally represent 1/sin and 1/cos, are used instead to indicate the inverse functions arcsine and arccosine.
@khanacademy My buddy actually used versine to prove a formula on a test in one of his calculus classes. He forgot what he was supposed to have memorized and ended up having to derive it.
Where was UA-cam when I was in High School? Kids have it so easy these days. Well of course not all kids, the digital divide is prevelant in so many parts of the world-it isn't even fair that these kids will have to compete against us.
I almost a 90% sure my math teacher watch your videos before teaching us, he says kind of the same stuff similar words and what not, but since is a simple topic probably is just casuality.
You need to watch ALL of sal's videos, you will find there is nothing like it. He proves the trig identities aswell, look on his channel for "trigoneometry" playlist heres a link to the playlist : /watch?v=ZWSoyUxAQW0&feature=BFa&list=PLD6DA74C1DBF770E7 If you dont do this, dont blame sal, blame yourself for being lazy :P
that is (sin^2(0)/cos(0))+(cos^2(0)/cos(0))=1/(cos(0)) that is ((sin^2(0))+(cos^2(0)))/cos(0)=1/(cos(0)) because sin^2(0)+cos^2(0)=1 there it is. ^2 means squared,i hate that notation
@lazmedina I am replying to an old comment but the argument is still relevant. It's not fair? Instead of being happy that people are being educated more easily, you say it isn't fair? That's ignorant and arrogant. It's a good thing no matter how you look at it.
video 14 in this (the trig) series. Note that he flipped how he wrote it here vs how he proofed it in video 14, but mathematically it works out the same.
@GangstaGriIIz as sad as it is too say. Textbooks don't really efficiently walk you through these formulas by repeating the basics then to the complex. They fail at khanacademy's logic.
Trigonometry unless you want to be a construction worker it's the second most boring and useless math topic ever. And the most boring and useless math topic is calculas
There are literally NO flaws in his methods of teaching.
If I had to give a flaw it would be for the the bad resolution on the old videos. But he now has HD versions, so in short, he's a beast!
That's interesting. I actually didn't know about them. I read about them after your comment. I might do some videos on this.
How awesome would Khan Academy be of it was in HD!
What are "them" cant find the original comment, and im intrigued by what has intrigued you great master!
The hypotenuse is 1 because of the unit circle (I don't know how else to put it). Just refer back to your unit circle and you will see that the radius is 1, which is also the hypotenuse. Keep in mind, that is ONLY on the unit circle.
"o" is just opposite, as in, side opposite of the angle (in this case V)
ur awesome man. u dont know how many people uve helped nail this subject. im learning right now. i have a test in a few days and thanks to you im going to pass :) god bless
Thank you very much for that useful information explaining the maths behind trigonometric identities. As a year 10 student it has really helped me get a grasp on some A level maths.
thanks you! you are best! we love you!
I love math! Shoutout to Mr. U!!!
thank you sir, you know ABSOLUTELY everything.
Around 1:20 you seem confused about why there is a secant and cosecant. The reason for that is because raising sine and cosine to the negative first power (sin^-1 or cos^-1), which would normally represent 1/sin and 1/cos, are used instead to indicate the inverse functions arcsine and arccosine.
Thank you, master
could you talk about the Ambiguous Case,i dont understand it,thanks
totally amazing and well taught
"Playing around." I might practice with them, but I go serious on these problems, I NEVER PlAy with them. Every one of these is a battle
@khanacademy My buddy actually used versine to prove a formula on a test in one of his calculus classes. He forgot what he was supposed to have memorized and ended up having to derive it.
And it is equal to "o" because you are dividing by 1 (because the hypotenuse is equal to 1)
❤❤❤❤this is great
U guys rock
Thwarted😊😊😊
@hgbpo its part of the double angle formula (cos2a) = cos^2a - sin^2x :)
you could even add cos²a+sin²a to cos²a-sin²a, which results in cos(2a)+1 = 2cos²(a) :D
thanks a million ... u saved my life
awesome video!!!
Where was UA-cam when I was in High School?
Kids have it so easy these days. Well of course not all kids, the digital divide is prevelant in so many parts of the world-it isn't even fair that these kids will have to compete against us.
Also not all kids can learn things from a UA-cam video. It's useful but not universally so.
thank you very much !! god bless i may actually have a chance at passing now
ur a life saver trust me ... where u frm??
I almost a 90% sure my math teacher watch your videos before teaching us, he says kind of the same stuff similar words and what not, but since is a simple topic probably is just casuality.
I get to school and hear teachers talk about *_*....then i get to youtube and itss like..wow i learned smethin new today...^_^
why did he prove sin(a+b) before he introduced it im hella confused
good not having heads in the way
You need to watch ALL of sal's videos, you will find there is nothing like it. He proves the trig identities aswell, look on his channel for "trigoneometry" playlist
heres a link to the playlist :
/watch?v=ZWSoyUxAQW0&feature=BFa&list=PLD6DA74C1DBF770E7
If you dont do this, dont blame sal, blame yourself for being lazy :P
thanks!
maybe i've missed something really obvious but: cscV = h/o = 1/sinV...
why is the hypotetenuse automatically = 1 and why is "o" = sinV?
thanks!
@MrTeeson that is incorrect my friend. cos2a = cos^2 a - sin^2 a
Good!
thank you! i love you man no homo this saved my life on the mid terms
@MrTeeson thanks :)
that is (sin^2(0)/cos(0))+(cos^2(0)/cos(0))=1/(cos(0)) that is ((sin^2(0))+(cos^2(0)))/cos(0)=1/(cos(0)) because sin^2(0)+cos^2(0)=1 there it is. ^2 means squared,i hate that notation
About "versine's"
you sound like seananners that does the call of duty commentaries
fun and amazing :D
at 6:52 why is it 2sinacosa, isnt suppose to be 2sinacosb? sorry if i dont get itXD
This one is sin(2a)
how come when you're proving the cos(2a) identity, the sines suddenly become negative?
@GangstaGriIIz so true dude
Playing around with trigonometry :P
@lazmedina I am replying to an old comment but the argument is still relevant. It's not fair? Instead of being happy that people are being educated more easily, you say it isn't fair? That's ignorant and arrogant. It's a good thing no matter how you look at it.
functions test hero
You misspelled "part" in the title.
where is the proof video of
sin(a+b)?
video 14 in this (the trig) series. Note that he flipped how he wrote it here vs how he proofed it in video 14, but mathematically it works out the same.
For written help with trigonometry, check out: fiverr.com/cheezees
Who else is here for COVID-19?
Hi Im TÜRK
I almost a good in English
Bill SinB/TanB
Thumbs up if you get it :)
@HypeeTommy cheayea xD
Your title is spelled wrong.
@soulestazn lol...
@GangstaGriIIz
as sad as it is too say. Textbooks don't really efficiently walk you through these formulas by repeating the basics then to the complex. They fail at khanacademy's logic.
ummm wtf where is part 4?...
this didn't teach me. I need to see someone do examples of trig identities he just gives me what the formula sheet says.
is there proof for sin(-0)=sin(0)
...
mabelleave there is no such thing as negative 0. If you're trying to write Theta, then sin(theta) = -sin(-theta), and cos(theta) = cos(-theta).
Trigonometry unless you want to be a construction worker it's the second most boring and useless math topic ever.
And the most boring and useless math topic is calculas