Mikasa Posted May 21, 2014 Share Posted May 21, 2014 There is a problem on this take-home make up test for math for learning purpose. "Find the 24th term of the expansion of (2h - k)^26 using the binomial theorem" I've already found the answer via an online calculator, but I don't understand how to find this, and the teacher never taught us how to do these with a coefficient in the problem. Edit: This is the answer So the 24th term would be 239200h^4k^22, correct? Quote Link to comment Share on other sites More sharing options...
Realist Posted May 21, 2014 Share Posted May 21, 2014 I believe the answer is root squared. Quote Link to comment Share on other sites More sharing options...
Mikasa Posted May 21, 2014 Author Share Posted May 21, 2014 pls no troll, srs help needed Quote Link to comment Share on other sites More sharing options...
Extreme Scripts Posted May 21, 2014 Share Posted May 21, 2014 You looking for just a answer with working for the 24th term or would you just like a method to do it and you figure it yourself? Quote Link to comment Share on other sites More sharing options...
Mikasa Posted May 21, 2014 Author Share Posted May 21, 2014 You looking for just a answer with working for the 24th term or would you just like a method to do it and you figure it yourself? I found the answer online. This problem was on a test that I was supposed to do in class, so I have no idea how I'm supposed to come up with an answer through just doing work on paper / calculator to get to the right answer. I put in the answer in the OP Quote Link to comment Share on other sites More sharing options...
Extreme Scripts Posted May 21, 2014 Share Posted May 21, 2014 (edited) I found the answer online. This problem was on a test that I was supposed to do in class, so I have no idea how I'm supposed to come up with an answer through just doing work on paper / calculator to get to the right answer. Alright so basically to find any term in the sequence we can use this formula:nCr.a^n-r.b^r Where n = power index a = first variable in bracket i.e. 2h b = second variable including sign i.e. -k . = Multiply coefficients r = term your trying to find The nCr button is on your calculator, let me know if you need further explanation I'll hop into chat. Edited May 21, 2014 by Divinity Quote Link to comment Share on other sites More sharing options...
Aza Posted May 21, 2014 Share Posted May 21, 2014 (edited) okay. what you want to do to find the 24th term is (NCR) x a^n-r x b^r the C stands for C, if you've done statistics it'll be on your calc. n where n is 26 in this case a would be 2h r is 24 that = 1300 on my calculator so i am right FFS SOMEONE ALWAYS POSTS LIKE A SECOND BEFORE ME... edit: the 24th term would be 26C24 x 2^2 x 1^26 Edited May 21, 2014 by Aza 1 Quote Link to comment Share on other sites More sharing options...
Mikasa Posted May 21, 2014 Author Share Posted May 21, 2014 Alright so basically to find any term in the sequence we can use this formula: nCr.a^n-r.b^r Where n = power index a = first variable in bracket i.e. 2h b = second variable including sign i.e. -k . = Multiply coefficients r = term your trying to find The nCr button is on your calculator, let me know if you need further explanation I'll hop into chat. okay. what you want to do to find the 24th term is (NCR) x a^n-r x b^r the C stands for C, if you've done statistics it'll be on your calc. n where n is 26 in this case a would be 2h r is 24 that = 1300 on my calculator so i am right FFS SOMEONE ALWAYS POSTS LIKE A SECOND BEFORE ME... edit: the 24th term would be 26C24 x 2^2 x 1^26 My brain just exploded. I have a basic bitch calculator, so I don't have that button :p Quote Link to comment Share on other sites More sharing options...
Extreme Scripts Posted May 21, 2014 Share Posted May 21, 2014 My brain just exploded. I have a basic bitch calculator, so I don't have that button :p Dayum that sucks, the long way is such a killer. Do you not have a scientific calculator? Quote Link to comment Share on other sites More sharing options...
Mikasa Posted May 21, 2014 Author Share Posted May 21, 2014 Dayum that sucks, the long way is such a killer. Do you not have a scientific calculator? This is what I have, which I am borrowing from the library - http://education.ti.com/en/us/products/calculators/scientific-calculators/ti-30x-iis/tabs/overview I should probably invest in a good calculator, since what I want to major in requires a lot of math classes ._. My teacher just kind of sucks and never taught us how to go this far into the expansion, especially if there is a coefficient, so I'm lost. Quote Link to comment Share on other sites More sharing options...
LTS Posted May 21, 2014 Share Posted May 21, 2014 Gotta love my TiNspire CX Cas Quote Link to comment Share on other sites More sharing options...
Extreme Scripts Posted May 21, 2014 Share Posted May 21, 2014 This is what I have, which I am borrowing from the library - http://education.ti.com/en/us/products/calculators/scientific-calculators/ti-30x-iis/tabs/overview I should probably invest in a good calculator, since what I want to major in requires a lot of math classes ._. My teacher just kind of sucks and never taught us how to go this far into the expansion, especially if there is a coefficient, so I'm lost. That will do, you see the "PRB" button? One button underneath it, A/Something press it and you should get the nCr option ^_^ Quote Link to comment Share on other sites More sharing options...
BurritoBug Posted May 21, 2014 Share Posted May 21, 2014 i thought math was numbers. Quote Link to comment Share on other sites More sharing options...
Aza Posted May 21, 2014 Share Posted May 21, 2014 A scientific calculator will cost like £10. I've had mine for 6 years now, hasn't run out of battery and does everything i need it to. Casio Natural Display FX-83ES Unless you find drawing graphs and such hard spend £50/60 on a graphics calculator and it'll literally be your bitch, just make sure you can take it into exams. Quote Link to comment Share on other sites More sharing options...
Mikasa Posted May 21, 2014 Author Share Posted May 21, 2014 That will do, you see the "PRB" button? One button underneath it, A/Something press it and you should get the nCr option I clicked it & it gave me this symbol & as you said, a = first variable in bracket i.e. 2h, so I'd input the h as well? can't seem to figure out how to do variables on this calculator. It's 3 am, I feel like dying at this point A scientific calculator will cost like £10. I've had mine for 6 years now, hasn't run out of battery and does everything i need it to. Casio Natural Display FX-83ES Unless you find drawing graphs and such hard spend £50/60 on a graphics calculator and it'll literally be your bitch, just make sure you can take it into exams. Yeah, I want to get a graphing one, I suck dick at graphing. My current problem I'm working on is "Graph the following equation and using that graph tell which is true: x^2 + y^2 - 2x + 6y = 6" Quote Link to comment Share on other sites More sharing options...
