Seniorstatus14 Posted April 5, 2014 Share Posted April 5, 2014 So this is an insanely off topic post, but I'm incredibly desperate. I have a few math practice tests that are going to be counted for quiz grades and I'm working through them, but I honestly need help with some things (mostly trig/ calc). It's really stressing me out because I have my IB tests starting exactly 1 month from today and these are past exams that we're using as practice and I can't figure this out! I found the answer key to the packet, but I still can't figure it out! I don't want to just copy answers because I know the test is coming soon and I need to figure this out!I'm working on the no-calculator part (which is usually my stronger section).One of the questions I'm having trouble with says: The straight line with equation y= (3/4)X makes an acute angle (theta) with the x-axis.I understand that tan (theta) is (3/4) but then it asks me to find sin2(theta) and cos2(theta). I understand how to do the math one I get the values, but I don't understand how to get the beginning values for sin and cos.The other questions I have have a picture that goes with them. If I find it online I'll post it on this thread.Please help if you understand!!! The answer key says sin= (3/5) and cos= (4/5) I just don't know how they got those values!! Link to comment

Paul Posted April 6, 2014 Share Posted April 6, 2014 I've solved it on paper and will PM it to you Link to comment

Seniorstatus14 Posted April 6, 2014 Author Share Posted April 6, 2014 I've solved it on paper and will PM it to youThank you! Thank you, thank you, thank you, thank you!!!!! Thank you X1000000000! Link to comment

bloom Posted April 6, 2014 Share Posted April 6, 2014 I'm not trying to be a jerk or anything, but how is somebody solving it on paper and PMing it to you going to help you actually learn the concepts? I feel like when it comes to the test you're still going to have difficulty understanding it. Maybe I'm missing something. Link to comment

tma Posted April 6, 2014 Share Posted April 6, 2014 I personally think that for getting the concepts- if you don't get it from a tutor at your school or tutoring from your teacher, that you are *much* better off finding an educational Youtube video that explains the concepts.I have friends that teach upper level maths classes that could probably recommend some of those types of sites, and I can put them in here, if you want. Link to comment

Seniorstatus14 Posted April 6, 2014 Author Share Posted April 6, 2014 I'm not trying to be a jerk or anything, but how is somebody solving it on paper and PMing it to you going to help you actually learn the concepts? I feel like when it comes to the test you're still going to have difficulty understanding it. Maybe I'm missing something.He showed me the steps to getting the (3/5) and (4/5). I didn't realize that I had to graph the y= (3/4)xI knew how to do the actually trig part after that, I just didn't understand how they got the beginning part So now I understand how to start the problem. Link to comment

Seniorstatus14 Posted April 6, 2014 Author Share Posted April 6, 2014 I personally think that for getting the concepts- if you don't get it from a tutor at your school or tutoring from your teacher, that you are *much* better off finding an educational Youtube video that explains the concepts.I have friends that teach upper level maths classes that could probably recommend some of those types of sites, and I can put them in here, if you want. Yes please!!! I use CrashCourse for Biology, but they haven't done math yet. They've done Bio, Chem, English, and now they are doing Psych, but still no math :/ Link to comment

tma Posted April 6, 2014 Share Posted April 6, 2014 I CrashCourse- they are flippin' *awesome* - I have no idea why more middle school/ high school teachers don't take advantage of them.Vihart has really interesting maths videos, but... it isn't as direct, step-by-step concepts. I'm gonna msg. my friend and will see what she comes up with. Link to comment

Seniorstatus14 Posted April 6, 2014 Author Share Posted April 6, 2014 I CrashCourse- they are flippin' *awesome* - I have no idea why more middle school/ high school teachers don't take advantage of them.Vihart has really interesting maths videos, but... it isn't as direct, step-by-step concepts. I'm gonna msg. my friend and will see what she comes up with. Thanks! My Biology teacher started us out with Bozeman. He's alright, but a little dull during the longer videos. Then last fall we had an assignment to find an interesting video that explained a certain concept and a girl in my class found CrashCourse and ever since then our class has been in love with it! Love John and Hank Green. They make learning fun and interesting! Link to comment

everest Posted April 6, 2014 Share Posted April 6, 2014 I'm glad you got help for that problem! I'm taking AP calc this year, and I like to use Khan Academy videos for math videos. They're on YouTube and they've got a website that apparently has free example problems and help forums. I've only ever watched a couple videos on YouTube, but they were really helpful to me.This may get slightly off-topic, so I'm sorry in advance. Also, I'm just speaking for myself here; I'm sure everyone has a different way of learning than I do. As far as seeing examples verses learning the concepts... obviously concepts have their importance. However, as a math student, I have to say that sometimes examples are just as, if not more, helpful in learning how to do problems. Sometimes, the issue is simple and an example clears it up. Other times, examples help solidify understanding. I can't speak for every student out there, but at this level of my math education, I view examples in a different way than just memorizing the steps. Most of the time, by the time we get to doing problems in our class, we've been taught the concept behind the math so we can sort of imagine what is happening. It's the actual math that tends to complicate things.When viewing examples, with all of the work shown, I usually go through it step by step and make sure I understand what's going on between each step. Having the loose understanding of the concept is helpful for this, granted. But by analyzing examples this way, I'm able to gain a more solid understanding of the math, because I had to work some of it out in my head, on my own. Hopefully that makes sense!Once again, sorry for going off-topic there! But this is one of the things that I'm kind of passionate about since I'm currently struggling through it myself. Link to comment

OCC Posted April 6, 2014 Share Posted April 6, 2014 If you have a textbook by Ron Larson, you should check out the website CalcChat. It's completely free. I think it covers precalculus and calculus stuff, but I'm not 100%. It has answers to odd numbered questions as well as explanations. There are also tutors who you can contact sun-thurs from 4pm-12am. Link to comment

Paul Posted April 6, 2014 Share Posted April 6, 2014 I'm not trying to be a jerk or anything, but how is somebody solving it on paper and PMing it to you going to help you actually learn the concepts? I feel like when it comes to the test you're still going to have difficulty understanding it. Maybe I'm missing something.There may have been better ways to do it, I'm not the greatest teacher, but I think that the graph I drew explained it pretty well in a way that she understood. Obviously I wouldn't have done a whole assignment, but given that she was stuck on a problem after trying many times I think the solution was helpful. Link to comment

Heathcliff Posted April 6, 2014 Share Posted April 6, 2014 So this is an insanely off topic post, but I'm incredibly desperate. I have a few math practice tests that are going to be counted for quiz grades and I'm working through them, but I honestly need help with some things (mostly trig/ calc). It's really stressing me out because I have my IB tests starting exactly 1 month from today and these are past exams that we're using as practice and I can't figure this out! I found the answer key to the packet, but I still can't figure it out! I don't want to just copy answers because I know the test is coming soon and I need to figure this out!I'm working on the no-calculator part (which is usually my stronger section).One of the questions I'm having trouble with says: The straight line with equation y= (3/4)X makes an acute angle (theta) with the x-axis.I understand that tan (theta) is (3/4) but then it asks me to find sin2(theta) and cos2(theta). I understand how to do the math one I get the values, but I don't understand how to get the beginning values for sin and cos.The other questions I have have a picture that goes with them. If I find it online I'll post it on this thread.Please help if you understand!!! The answer key says sin= (3/5) and cos= (4/5) I just don't know how they got those values!!We start with the line y = (3/4)x Imagine a right-angled triangle with hypotenuse running along that line, and has base length 1: it has vertices at (x,y) = (0,0) , (1,0) , and (1,3/4)Look at that triangle: it is easy to see that that the two sides which are not the hypotenuse have lengths 1 and 3/4. We want to know the length of the hypotenuse (call it c) so we use Pythagoras' theorem:c^2 = (1)^2 + (3/4)^2 = 1 + 9/16 = 25/16So, c = 5/4 (the length of the hypotenuse of our triangle.)Now... we are told theta is the angle between the x-axis and the hypotenuse y = (3/4)x .Using our triangle: remember the rules: tan = opposite / adjacentsin = opposite / hypotenusecos = adjacent / hypotenuseOur lengths are:opposite = 3/4adjacent = 1hypotenuse = 5/4Calculate sin(theta) and cos(theta) with those values:sin = (3/4) / (5/4) = 3/5cos = 1 / (5/4) = 4/5Hey presto! Link to comment

Seniorstatus14 Posted April 6, 2014 Author Share Posted April 6, 2014 Thanks guys! Now I have more resources to study for this upcoming exam!@everest I know what you mean. We use the "flipped classroom" in a few of my classes which mean that we go over a concept by ourselves the night before class and then when we get to class all we do are practice problems with the teacher. The examples he does are so much more helpful than just reading the textbook over and over.Thank you all once again Link to comment

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