basically what Kristian Brasel is saying..."hey guy taking the time to make a nice tutorial to help others for free. I feel like complaining" =/ Kuddos for Sick Puppies in the background :)
Justin Burton it would be a nice tutorial if there wasnt music blaring in the background. it makes it hard to focus. I am just trying to give some constructive criticizm. quite a few people agreed with me.
im not trying to troll the guy, just let him know. he could have just as easily made the video with no music, and if he makes another one (which people on youtube tend to do) than maybe he will take the criticism and make a much more pleasant video next time. his video got a good amount of views, people make decent money off of youtube, if that is his intention than i would think he would welcome any constructive criticism people have to offer. plus, even if he made the video just to help other people than you would think he would actually care to know how he could make it better. you guys are acting like i just insulted the guy, if you cant take criticism than you shouldnt be on youtube.
For *bigger* numbers, (120°, 135°, 150°, 180°), the trick still works, but *for sin*, for every angle, instead of 0, 1, 2, 3, 4 like in the video, count down from 4 to 3 to 2 to 1 back to 0. So, if sin90 is sqrt4/2, sin120 will be sqrt3/2, sin135 = sqrt2/2.... so on. *For cos*, you have to count up, so from 4, 3, 2, 1, 0 in the video, for every angle, it goes from 1 to 2 to 3 to 4, but add negative (-) in front. So say cos90 = 0, then cos120 = -sqrt1/2, or -1/2, cos135 = -sqrt2/2, cos150 = -sqrt3/2.... so on.
Use the concept of reference angles; since 330's in quadrant 4, you subtract it from 360. (360-330 = 30). Use the sin/cos values of 30 but change the signs and since the angle is in QIV then it's y-values (sin) are negative. Sin30 is 1/2 and sin 330 is -1/2. The same goes for other reference angles
No joke, I have a midterm and I've missed so many classes, and haven't taken trig in 10 years. I've been teaching myself online for the exam for 5+ hours. This 6 minutes video did more for me than ANYTHING I've looked out. You're seriously the man.
Omg! Thank you so much! Unlike every other tutorial I've seen, yours was the simplest and clearest! Everyone else's was just so confusing ! Yours is the best. Though your music is a bit distracting but it saved my life. I should have noticed this sooner!
You explain it better than the teachers. All I could find was "This is what it is because it is." None of them ever really "Explain it." Good job, dude.
if you can use a calculator but your stuck with a crippled Board-approved POS, just enter the question (ie sin45), square it (remember to press the S 》D button), and then root of the top and bottom numbers.
@kiojose Sorry for the lack of reply but as a college student I don't have a lot of time in my hands, but to answer your question there are several ways to figure it out, but the easiest and using the "trick" above would have to be using your imagination, first subtract increments of 360 to 1200 until we get it to a value below 360. So if you subtract 360 3 times your left with 120 degrees. Then we picture the unit circle in our mind, we know that in quadrant 2(between 90 and 180) the value 120
holy, this is a life saver...up to this point I only knew how to get common angles between 30 and 60 without memorizing stuff! Now I know how to get 90 and 0 as well !!! And I just realized I can get 180 by negating the exact values!!! Thanks man.
If you use a ti-84 Plus just hit math then Frac to convert a decimal into a fraction. To make every answer come out as a fraction hit mode, go to the second page and where it says answers choose FRAC. I think it should be the same on other 84's and 83's. I know its the same on the TI-84 Plus Silver Edition.
Thanks, you saved my butt. Taking a test for a job promotion/bid and I couldn't seem to memorize the chart. This makes much more sense than memorizing a chart.
This helped SO much. My exam board don't want the values rationalised, but with this method, only sin45 and cos45 need to be rationalised and it is REALLY easy.
Sin is a measure of how much perpendicular two objects are. Hence sin(90)=1. Cos is a measure of how much parallel two objects are Hence cos(0)=1. Sin comes into picture when two things produce maximum effect working against each other. Cos comes into picture when two things produce maximum effect working parallel to each other. There are videos dedicated to trignometry on my channel if you. Actually also have a book written on such topics. Binnoy
I HAVE A TRIG AND ALGEBRA FINAL TOMORROW I SPENT SO MUCH MONEY FOR THIS CLASS I AM SOLID WITH THE ALGEBRA BUT A BIT UNSURE WHEN IT COMES TO THE TRIG STUFF THIS HERE IS CHANGING MY LIFE I LOVE YOU SO MUCH I WILL SCK YO' DCK FO' FREE.
don't worry i can relate, I've been out for the same amount of time and its hard to remember the old stuff , well i don't know what other stuff are in the ASVAB but i heard its not that difficult, and ive been really busy lately :( i will try to get back to youtube videos as soon as possible and just a tip if all else fails when factoring always go to the quadratic formule :) goodluck!!
@kiojose exists which is the same as 1200 right?, after that we know that coming from the right(where the 90 is) toward the 180,120 degrees is 30 degrees more and coming from the left is 60 degrees more, so from the left (180) we know that its 60 degrees, so we take tan 60 and we know its sqrt(3),but since its in quadrant 2, we know that its going to be negative since only the sin values are positive :). I hope you understood my long explanation lol ill try to explain it better in a video using
so therefore, If I was evaluating 65 degrees multiplied by sine I would get 3 1/6, since there are six 5's from 60 to 90 and 60sine is equal to 3 and 90sine is equal to 4. I'm stuck on evaluating Tan65 degrees so I could use some help. Cheers!
wish I had seen this before taking any entrance exams....YOU ARE SO AMAZING! NEVER HEARD ABOUT THIS BEFORE. please upload more tricks that would make our lives easier.
Hi RelearnMath, I suggest u next time u should turn off the music because it makes me (and probably some other people) get distracted a lot because I tried to listen to what you are trying to say.
@comeon7894 I should have explained reference angles in the video because I get a lot of these questions on my inbox lol, ok for sin(240) we first find the reference angle, 240 is the same as 60 degrees except that its in quadrant 3(picture the unit circleit in your head ), so we use the trick for sin(60)and we get [sqrt3/2] but since sine is negative in quadrant 3 that answer is [-sqrt3/2]
I am trying to compute pi and unfortunately, i can't compute the sine of numbers like 9*10^(-8). Could you teach another trick for numbers less than 1? If possible, of course. ;) Nice video, by the way!
@xBazingaProductionsx No it wouldn't work sorry, but you can just find the reference angles of higher degrees and use the "trick" for it. For example the sin(135) = sin(45) because 45 is the reference angle but in quadrant 2, since we know all sine in quadrant 2 are positive then the answer is the same
You helped so much! This method is genius! I would've never been able to memorize the 30,60,90 and 45,45,90 triangles! You don't need to even know them without this amazing method! Thank you!
I don't care about the distracting hardcore rock in the back, the random black dots all over the paper, or even the crappy editing; THIS VIDEO IS PERFECT
Whew! It is ashame i do not remember this work and I've only been out of high school two years... Thank you soooooooooooo much... I am studying to take the ASVAB, do you think you could make a video of factoring... Ex: v2-2v-15 the v is squared...
thats the real learning not all thing u need to learn need to memorize i can say that understanding analysis retains or last long than memorize then later 4get
Thank you so much for this trick. I wish professor's would learn tricks like this. If you can keep the paper in one place, it would greatly help the future viewer. Thanks again.
This is awesome! One issue though... What if you have an angle greater than 90 degrees? Can you still use that basic set up but use the coterminal angle? For example, a question on my assignment says: "Find the exact value of sin(1290*)" How would I go about that using this method? I would love a video over that!! Thank you :)
if sin8° = m what is sin74° how can you solve this? i think it should be related to unit circle but dont know exactly how. any help would be appreciated
I had about 3 other ones that needed editing but my computer messed up and I just recently bought a new one :/, anyway I will get back to making videos ASAP when I finish midterms,
Thank you soooo much for the trig trick, do you have any new stuff that relates to identities and such? Its getting trickier for me and I need the help. THANKS!!!!
I was breaking my head trying to find out how to calculate these with an equation (using the ratio of the spuared sinus and cosinus) but I always ended up only finding the equations leading to rounded graphs which you can't perfectly describe with an equation (calculus leaves parts out so it isn't describing it exactly). I asked my teacher and he said that without calculator they just use lists with the side ratio-degree and the calculator uses software to measure the side length and degree. Hope that anwsered your question.
The only way to get an exact value(really its just a really close approximation) of Sin/Cos/Tan by plugging into an equations is by using infinite series. You can google, Sine Taylor Series and you should be able to find it, theoretically, if you use an infinite number of terms you will get the exact value, however if you simply want a really good approximation you only need to use a few of the terms. I have a video where I use 3 or 4 terms(i forget) and it is enough to give me the calculator value. So for all intents and purposes it's good enough.
You got "lucky" with the simplest angles, because they all come from the geometry of a hexagon. But you won't be so lucky with, let's say, 36°, 72°, 18° (still quite lucky, though, since they're based on the geometry of a pentagon/pentagram, so they're full of golden ratios), or even some "round" ones like 20°, 40°, 50°, 70°, 80° (based on the 9-gon). Not to mention stuff like cos(√2) or cos( √(-1) ) :D
hey, would it still work if we continued using angle measures from the unit circle? For example, instead of just going from 0 to 4, we could go to like, 0 to 10, with the correct corresponding angle measures from the unit circle of course. let me know, thanks :)
Nice keep it up man, you foundation will make things easier in the future if your good at geometry and algebra and really understand the concepts behind the math then more advanced classes will become easier, I learned this the hard way.
