For cos 2x there are 3 possible formulae 1.) cos 2x = cos²x-sin²x The next two are obtained from Pythagorean Identities First cos²x = 1-sin²x cos 2x= 1-sin²x-sin²x 2.) cos 2x = 1-2sin²x And also sin²x= 1-cos²x Reverting to the first formula and substitution we get cos 2x = cos²x-(1-cos²x) We finally have 3.) cos 2x = 2cos²x-1
I was so afraid I would not understand how to do this. I kept telling myself nothing is impossible! I watch your videos and feel like I can learn even the most confusing topics. My teachers are no help of showing how they got an answer- they only show the answers. Thank you for making this so simple to understand!
I had many tabs open explaining the same concept just in case I did not follow along well with the teaching, but I didnt need to choose another video... this one was it
Thank you so much!! I was staring at my textbook for like a half an hour straight and literally none of the words didn't make sense. I didn't realize it was this simple all along!
Great video! Very helpful!! Will definitly be subscribing for more help in the future! Keep teaching the way you do its amazing and better than any professor who cant ctrl+Z or use shortcut commands! Very swift and efficient!
Just a heads up, the commercials that come along during your videos are perhaps 50 decibels louder than you. It's quite jarring to go from a calm explanation of math to an overwhelmingly loud ad. Totally happy to support you with ad placement, but maybe turn up a tad? Other than that, i'll probably owe my degree to you when it's over.
The fact this man has saved so many grades and helped so many people without even being in person is proof our current education system sucks worse than a random dude on UA-cam.
the only way to help this guy back is to watch the ads that popping out on his video and I'm going to write this comment to all of his video for you to know you can help him back by just watching his ads
What would be so awesome, for people like me is if you could rewind in 15 second increments. Is that a feature you can turn on? I see it in some videos, and it’s good when I go, what was that again...? My big finger goes back minutes not the thing you just said. Your videos are an inspiration, thank you So Much!
@TheOrganicChemistryTutor @8:10 why did you multiply the numerator and denominator by 16 instead of creating common denominators and multiply by the reciprocal? I fully understand that your method is valid and a slightly different approach, I've just never taught it this way.
Our teacher asked us to work the problem out in bold on paper and hold it up. I scribbled organic chemistry tutor as legible as possible and held it up.
theres only 2 triangles, the first one has two 45 degrees and one that is 90 degrees. and the other one has 60 and 30 degrees and one 90 degrees. so in conclusion there's onyl 3 angles that you can only use when finding the exact value of any of the trigonometric ratios. you cannot write any other angle. OR.. you can just skip the special triangles and type the trigonometric ratio with its angle on the calculator and you'll get the exact value with that. one thing to keep in mind is if the answer was √a/a on the calculator you write 1/√a instead. FOR EXAMPLE; tan(30) = √3/3 *on calculator* but if you use the special triangle you will get 1/√3. hope that made sense.
I'm genuinely curious what is the actual difference between a teacher doing this in class and me watching this video. Is it the intent? Is it because I searched this up purposely? Is because I get easily distracted in a classroom? I don't know why it's so easy to understand these videos and so hard when it's in class or in a book!? Does anyone have any idea why?
So these videos are great and all but one of the questions I'm having to answer, is simplifying 6 sin 5x cos 5x. Would the sin 5x be 5 sin theta cos theta, instead of 2? I have 0 ideas for how to do the cos 5x lol. Maybe 5 cos^2 theta - 1?
because finding the quadrant first lets u know what sign ur answer needs to be. so if the quadrant is 3 and you're finding the value of cosine, then you don't have to worry about signs while figuring out the value and just put the negative sign at the final answer, (since cosine is always negative in quadrant 3). the trick is: ASTC. A= all positive in Q1. S= sine and csc positive in Q2, everything else negative. T= tangent and cot positive in Q3, everything else negative. C= cosine and sec positive in Q4, everything else negative. hope this helps :)
What if there is a question that requires the answer like if there is given (sin tita=3/5) and (cos tita - 4/5).The cos2tita =7/25...my question is how can we make reciprical to find its (sin tita=3/5)and (cos tita - 4/5)..please help me..
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Omggg you explained better in 5 minutes what my teacher couldn't in 2 hours. Thank you so much!
🤣🤣🤣
Or you weren't listening and paying attention in class.....🤣🤣🤣😂😂😂
@@joshmick or some people just have bad teachers...
Damn
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I’m so happy I found your channel. You are helping me to understand the subject better and save my grade one vid at a time!
the fact that I learned a whole weeks worth of lessons in 10 minutes really says something. You are the absolute best my friend!
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What to do when UA-cam teaches you better than the *pre-recorded* videos on your *school's* website: 🤨
Same, it’s much better than our school videos 💔
Ikr -_-
Felt this
the difference is competition
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I allways struggle with the Tangent equation, but the way you showed it, its so clear.
Youve helped me throughout the years, really wanted to thank you for posting these videos you have no idea how many lives you change
MR. Organic Chemistry Tutor, thank you for a fantastic video on Double Angles Identities and Formulas of Sine, Cosine and Tangent.
Your content is amazing! And sooo sooo sooo helpful!
For cos 2x there are 3 possible formulae
1.) cos 2x = cos²x-sin²x
The next two are obtained from Pythagorean Identities
First cos²x = 1-sin²x
cos 2x= 1-sin²x-sin²x
2.) cos 2x = 1-2sin²x
And also sin²x= 1-cos²x
Reverting to the first formula and substitution we get
cos 2x = cos²x-(1-cos²x)
We finally have
3.) cos 2x = 2cos²x-1
Thank you so much. ❤❤❤
I was so afraid I would not understand how to do this. I kept telling myself nothing is impossible! I watch your videos and feel like I can learn even the most confusing topics. My teachers are no help of showing how they got an answer- they only show the answers. Thank you for making this so simple to understand!
I had many tabs open explaining the same concept just in case I did not follow along well with the teaching, but I didnt need to choose another video... this one was it
why are you better than my last 4 teachers combined ( my whole of highschool math)
😆😂
Unbelievable. You are the best teacher I've ever watched... Thank you soooooo much ... You brought my life back ..
100% agree with u in this
This helped a lot! I got a quiz on this right now 😨
U explained this in a space of 3 minutes and I understood unlike my teacher who had to stand in front of me for 2 hours but no understanding ❤️
You're a phenomenal teacher!
Thank you so much!! I was staring at my textbook for like a half an hour straight and literally none of the words didn't make sense. I didn't realize it was this simple all along!
Great video! Very helpful!! Will definitly be subscribing for more help in the future! Keep teaching the way you do its amazing and better than any professor who cant ctrl+Z or use shortcut commands! Very swift and efficient!
I like the cool way you used to prove the double angle identities, thank you!
This really helped me with double angles, thank you so much 🙏
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I love watching it get proven so swiftly thanks
Just a heads up, the commercials that come along during your videos are perhaps 50 decibels louder than you. It's quite jarring to go from a calm explanation of math to an overwhelmingly loud ad. Totally happy to support you with ad placement, but maybe turn up a tad? Other than that, i'll probably owe my degree to you when it's over.
cope
@@uncle_sanguine852 or provide feedback that helps. Shhhh
@@shaynerushton214 cope
people r dying kim
you're much better! direct to the point explanation ❤❤❤❤
Excellent explanation, I am really enjoy obtaining and watching all your videos 👏👏👏
Thank you so much.
Your videos really helped me a lot.
It was easy to understand
Probably your are the best sir you know how to simplify things in your explanations
holy-- i love u so much thanks for helping me in math TT
This guy literally teaches better than my school right now
Thank you alot i will always remember u in my prayers
The fact this man has saved so many grades and helped so many people without even being in person is proof our current education system sucks worse than a random dude on UA-cam.
the only way to help this guy back is to watch the ads that popping out on his video and I'm going to write this comment to all of his video for you to know you can help him back by just watching his ads
جزاك الله خيرا
Thank you
Your channel is like thesaurus for maths. Whenever I don't understand sth, i look that up here.
Bro that makes so much sense thank Goodness for youtube and you cuz I was so confused 😂
Thank you for saving me from my math tutorial class.
The sin 2x/cos 2x is the best trick for tan 2x
Are you a mind reader because I said that exact thing in class and my teacher gave me bonus points for finding a simpler way.
Same in mind as well
@@julietokonko4274 My Senior High Math Doctor taught me this trick
that was very easy to understand bruh... thanks
Wow this is a very nice explanation am so grateful bro
dude you're the best
What would be so awesome, for people like me is if you could rewind in 15 second increments. Is that a feature you can turn on? I see it in some videos, and it’s good when I go, what was that again...? My big finger goes back minutes not the thing you just said. Your videos are an inspiration, thank you So Much!
i'm 2 years late but in case anyone is wondering, pressing the left arrow will rewind a video by 10 seconds
Complete Formula;
for sine - 0:51
for cosine - 1:51
for tagent -2:51
You're the best,Thank you so much 😊😊😊
Another great video, thanks for posting
Bro u are a magician 😂😂😂😂😂😂I swr how did I understand this soooo fast
Love watching your videos
@TheOrganicChemistryTutor
@8:10 why did you multiply the numerator and denominator by 16 instead of creating common denominators and multiply by the reciprocal? I fully understand that your method is valid and a slightly different approach, I've just never taught it this way.
Thank you, now I understand better
I will sleep less stupid
Thx a lot I don’t know how to thank u U R amazing 💋💋
Great teacher . thanks ❤
thank you po
You just saved me dude, 🎉... Couldn't get this in class yapa Luanar (Bunda campus)
thank you so much!💛
you are my best mathematics teacter
Yeah you need a better English teacher my dude🤣
Our teacher asked us to work the problem out in bold on paper and hold it up. I scribbled organic chemistry tutor as legible as possible and held it up.
My only problem is finding this out right at night before the test 😩
Best tutor well explained
how do you know what type of triangle you have?
theres only 2 triangles, the first one has two 45 degrees and one that is 90 degrees. and the other one has 60 and 30 degrees and one 90 degrees.
so in conclusion there's onyl 3 angles that you can only use when finding the exact value of any of the trigonometric ratios. you cannot write any other angle.
OR..
you can just skip the special triangles and type the trigonometric ratio with its angle on the calculator and you'll get the exact value with that. one thing to keep in mind is if the answer was √a/a on the calculator you write 1/√a instead.
FOR EXAMPLE;
tan(30) = √3/3 *on calculator*
but if you use the special triangle you will get 1/√3.
hope that made sense.
why even go to class if I can just watch your vids and understand in literally 1/4th the time
This is 1000x better than Virtual High school. Never do a course with their online program.
I'm genuinely curious what is the actual difference between a teacher doing this in class and me watching this video. Is it the intent? Is it because I searched this up purposely? Is because I get easily distracted in a classroom? I don't know why it's so easy to understand these videos and so hard when it's in class or in a book!? Does anyone have any idea why?
So these videos are great and all but one of the questions I'm having to answer, is simplifying 6 sin 5x cos 5x. Would the sin 5x be 5 sin theta cos theta, instead of 2? I have 0 ideas for how to do the cos 5x lol. Maybe 5 cos^2 theta - 1?
nope, just realized it was a multiple of sin 2x lmao. It's 3 sin 10x.
Thanks for helping.
you sound like lil tecca if he was a teacher but good vid.
Dead
who is lil tecca
@@hummus9118 lmfao
@@storny1878 oafml
@@hummus9118 u doin p3 in jan?
idk anything about reincarnation but if it exists you're going to be the happiest, most fortunate person in your next life
TYSM
How do u know which quadrant the angles fall in... I don't know how to tell.
Compare angles to unit circle.
Joshua Bacchus
Pi is equal to 180
Quadrant 1 - 0 to 90
Quadrant 2 - 90 to 180
Quadrant 3 - 180 to 270
Quadrant 4 - 270 to 360
@@Meggutz this was very useful thx
Organic Chemistry Teacher is literally superior to my teacher.
Why isn't Cosine positive since its in quadrant 4?
May God bless you!
3:54 how did you get the 4?
Big help sir🙏🏻
Example number 2 when finding cos2Q.. I think you had to distribute the negative which would’ve resulted to 169/169.. I may be wrong
The 144/13 has a negative of course but it’ll be squared which will make it positive.
That was greaaaaaaaaat!
Why would you want sin(2x), or cos(2x) or tan(2x)? How can you use this information? I'm learning trig purely off UA-cam so I don't know these things.
why isnt the hypotenuse of the 5-12-13 triangle at 10 minutes negative? its in the 4th quadrant after all
someone please tell me why only the 12 was negative in the fourth quad while 5 and 12 were exempted
Yea i need to know too
THANK YOU
At 9:43
Why isn't the hypotenuse negative?
The hypotenuse is positive no matter which quadrant it is in.
how can you determine the type of triangle that it is?
JOHN 3:16
FOR GOD SO LOVE THE WORLD, THAT HE GAVE HIS ONLY BEGOTTEN SON, THAT WHOSOEVER BELIEVETH IN HIM SHALL NOT PERISH, BUT HAVE EVERLASTING LIFE
Helped so much.Thnx
So my teacher said we have to find the quadrants before solving the problem. But I don't know why?
because finding the quadrant first lets u know what sign ur answer needs to be. so if the quadrant is 3 and you're finding the value of cosine, then you don't have to worry about signs while figuring out the value and just put the negative sign at the final answer, (since cosine is always negative in quadrant 3). the trick is: ASTC. A= all positive in Q1. S= sine and csc positive in Q2, everything else negative. T= tangent and cot positive in Q3, everything else negative. C= cosine and sec positive in Q4, everything else negative. hope this helps :)
0:07 No I don't remember that equation
Thank you thank you thank you
cos(2x) = 2cosx-2sinx
❤️❤️❤️THANK YOU
thank youuuuu
the question is sin x = 1/7 so I did the formula and got sin 2x = 10 sqrt2 / 49 but my homework says its wrong i cant figure out why
what if the question is secant, cosecant and cotangent
What if there is a question that requires the answer like if there is given (sin tita=3/5) and (cos tita - 4/5).The cos2tita =7/25...my question is how can we make reciprical to find its (sin tita=3/5)and (cos tita - 4/5)..please help me..
whats the question exactly?
I don't understand how you figure out what quadrant theta is in
sin(x+y) = sinxcosy + sinycosx
how tan could be positive while theta is in q4? 12:56
sin(2x) = 2sinxcosx