what's going guys welcome back to today's video today we're going to go over questions on trigonometry if you know these question types you can solve any question that will come up on the SAT guarantee you will never miss another trigonometry question yet if it's your first time here my name's John and I've been helping students raise their SAT score to the moon for the past decade and today I'm going to teach you everything I know about trigonometry so you can raise your score all right let's get started trigonometry questions what do they look like how can you tell whether it's a trigonometric question there is a super-big indicator and that is they use the word sine or cosine and the question whenever you see cosine something sign something cosine something whatever that is going to be a trigonometry question and when it comes to these two questions you only have to know two types and what are those two types okay first one is going to be sohcahtoa you know sine of X sine of X is equal to opposite over hypotenuse so X is going to be the angle and opposite is going to be the length of the opposite side from the side of the angle and hypotenuse is going to be the hypotenuse the length of the hypotenuse of the triangle okay so the first type of a trigonometric question is sohcahtoa the second type is going to be something related to complementary rule and what is that complementary rule is a trig identity which says sine of X is equal to cosine of 90 minus X of course X's here are going to be your angle and just the opposite way cosine X is equal to sine of 90 minus X as long as you know these these two identities right here you can solve any questions that's relevant to complementary rule and you also want to remember that the angles on the inside are all you're always gonna add up to 90 for instance let's say this X is equal to 20 then it's going to be 90 minus 20 which is going to be 70 right 20 plus 70 and equals 90 so the angles on the inside will always have to equal 90 degrees that's what you have to remember and compliment your rule identity as well okay so that's what you have to know about complementary rule so let's go over how we can solve this question all right so let's look at the first question circuit all right so let's look at the question it says if the triangle above has the sine of X which is 0.6 and the question is wondering what is cosine of Y is going to be right so this one is going to be about sohcahtoa so question tell us the sine of X is equal to 0.6 right and whenever you see trick question and sine of X is equal to 8 decimal instead of a fraction always change it to a fraction because if you change the fractions 0.6 it's going to be 3 over 5 and we know that 3 is going to be opposite because sign is going to be opposite rap news and the bottom is going to be hypotenuse right if it's put in a decimal form like that right there there's no way for us to find out exactly what the length is and it just makes the question that much more difficult okay so whenever you see trick question right there always change to a fraction it's gonna make your life a lot easier okay so sine of X is 3 over 5 so X is right here opposite is Street and hypotenuse is going to be 5 and the question is asking for us to find cosine of Y okay so cosine of Y is equal to what cosine is going to be adjacent over hypotenuse so what's the adjacent of Y it's going to be 3 y is right here and adjacent is going to be the adjacent side which is going to be 3 and hypotenuse is going to be 5 okay so answer is going to be 3/5 or 0.6 it's the same thing okay so that's how I said he's gonna ask you about sohcahtoa second question is going to be about complementary rule so complementary rule is a trig identity which says sine of X is cosine of 90 minus X and cosine X is just sine of 90 minus X okay and let's look at this question right here it says in a right triangle okay one angle measures X where sine of X is 4/5 right and questions asking cosine of 90 minus X right so what most people could do is okay it's a right triangle so let me try to draw out a right triangle and see if that gives me something but let me let me give you a big hint whenever you see a cosine and a sine within the same question there's a very big chance it's talking about the complementary role so make sure you try out complementary role first before you do anything also something that really really gives it away that it's a complimentary real question is whenever you see 90 minus X in the question that's without a doubt 110 percent of the time it's always going to be about complementary role okay so two triggers are going to be sine and cosine within the same question just showing up together and second is if you see like cuss sine or cosine of 90 minus X whatever you see that that's a hundred percent chance it's complementary rule so always look up for those triggers okay so question telling us that sine of X is 4/5 right and they're asking us to find cosine of 90 minus X is equal to one and based on complementary rule we know that sine of X is same thing as cosine of 90 minus X which is this identity right here okay sine of X sine of X is equal to cosine of 90 minus X that right there so we know these two are going to beat the sink so cosine of 90 minus X is equal to 4 over 5 okay so our answer is going to be 4/5 okay so complementary rule what you need to know is these identities right here okay also another thing that you have to know about complementary rule is that the angles on the inside as I mentioned before they have to add up to 90 okay they have to add up to 90 if that's something you're not familiar with don't worry we're gonna go over that in a second in the lecture ok so that's how you solve these two questions right here okay and that's exactly how you solve those two types of questions about trigonometry that show up on the SAT actually that was a really skinny simplified explanation on how you saw these questions and why we do certain things but if you want to know more in depth it's gonna take way too much time for me to explain it in this video that's why I have prepared a separate lecture so if trigonometry is something that you're struggling with or you just want to improve your SAT skills overall there's going to be a link in the download description box down below where it it takes you to a private lecture on trigonometry where I give you everything you need to know about trigonometry and I go also go super in-depth okay and also there is going to be a worksheet that goes along with the lectures which you can download and just prepare now so you can just follow along what we do on the screen and then just do the practice problems and then we can go over that together okay overall it's a great lecture also after you finish the lecture there is also going to be a worksheet that goes along with it which is a just set up technology questions that actually showed up on the SAT before so you can try those questions and if you can solve all these questions correctly that's a pretty good signal that you are you are getting better at trigonometry and it's not something you should worry about and that's what we get guys that's literally all you have to know about your Nam tree at least for the SAT if you know how to solve those two types of questions completely inside out you will never miss another question about your Tom tree on SAT ever again if you guys liked the video make sure you hit the like button and if you guys love this kind of video make sure you subscribe to this channel because as a tutor I just know the inside and out of the SAT and on a weekly basis I'm going to put out these videos where I summarize what you need to know exactly what you need to know for certain chapters of the SAT whether it be reading writing or math and what you summarized in this simple video so that you guys don't have to spend hours and hours going through pages and pages try to either find out what you have to know for the SAT okay because some books on the SAT they don't give you everything they actually they give you everything but they just give you way too much stuff on the side that you don't really need to know and as a high school student as a busy high school student you don't have the time to just go through the fluff that doesn't need to show up in the SAT and my job is to come in and tell you exactly what you need to know and also if you guys have any questions or comment to make sure you leave them down in the comment box below and also if there is a topic that you want to see next time any kind of questions that you guys might have also leave them in the comment box below because the videos that make for this channel are heavily like literally heavily so heavily influenced by what you guys want to see next okay so leave them in the comment and I'll make a video about it if I can anyways guys it's 9:45 and I'm tired as hell so I'm just gonna end this video right here and I'll see you guys in the next one bye bye [Music] precious no-bullshit grown up in extra labor playing gays [Music]