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If I have a triangle with two sides 16.05 long, and the angle between these two sides is 17.1428571428, what is the length of the third side? How do I calculate this?Thank youWillieAn optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:google 'law of cosines'
Reply:4.784 is the length of the unknown side.I know enough about the 'law of cosines' to know it is useful. I use a calculator when I want a quick answer.http://www.calculator.net/triangle-c...its=d&x=45&y=4
Reply:willie; google is the new magic 8 ball. it knows all.
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Reply:I gotta buy one of those $100+ fancy calculators for my pre-calculus class this semester
sticks because I got a perfectly good Ti84/89 emulator on my tablet but the school won't let you use phone or tablet calculators for the tests. Sent from mobile. Not responsible for TyposTiger Sales: AHP Distributor www.tigersalesco.comAHP200x; AHP 160ST; MM350P, Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma. For Sale: Cobra Mig 250 w/ Push-pull gun. Lincoln Wirematic 250
Reply:
Originally Posted by soutthpaw
I gotta buy one of those $100+ fancy calculators for my pre-calculus class this semester
sticks because I got a perfectly good Ti84/89 emulator on my tablet but the school won't let you use phone or tablet calculators for the tests. Sent from mobile. Not responsible for Typos
Reply:
Originally Posted by Willie B
If I have a triangle with two sides 16.05 long, and the angle between these two sides is 17.1428571428, what is the length of the third side? How do I calculate this?Thank youWillie
Reply:
Originally Posted by MinnesotaDave
My favorite is the TI Voyage 200. Basically the TI-89 but with a qwerty keyboard and much easier to read screen.Used they are about $100 or less usually.For most stuff I just use a regular calculator that still has sin cos and tan buttons though.
Reply:Oh, that voyage is not permitted on most standardized testing due to keyboard feature. Guess you could type in a while cheat sheet. Most of the calculators now stateon the package if they are standardized test approvedTiger Sales: AHP Distributor www.tigersalesco.comAHP200x; AHP 160ST; MM350P, Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma. For Sale: Cobra Mig 250 w/ Push-pull gun. Lincoln Wirematic 250
Reply:
Originally Posted by soutthpaw
Yeah, the school still teaches on ti84. It seems really bass ackwards design that is a 20+ year old interface. So much for using the latest technology. I'm thinking about the Ti Nspire CAS or the HP prime if you are familiar with either of those. I'm gonna ask the first day of class. See what the professor recommends or is familiar using.
Reply:
Originally Posted by soutthpaw
Oh, that voyage is not permitted on most standardized testing due to keyboard feature. Guess you could type in a while cheat sheet. Most of the calculators now stateon the package if they are standardized test approved
Reply:
Originally Posted by MinnesotaDave
Nothing really wrong with the NSpire CAS, I just hate it personally.Trying to teach with it sucks when dealing with students who have never even used a TI-83.The whole class becomes about teaching how to use the damn thing instead of learning about mathematics, how to think about math, and it's practical uses.I would definitely vote for using a tablet - much more streamlined for most graphing applications in my opinion.Some students I taught were able to use the NSpire, but it wasn't very many in the type of schools I work in.
Reply:
Originally Posted by soutthpaw
Good to know. I'm hoping they have in class test loaner calcs then I'll just learn on the emulator and borrow one for tests. Here is how the 2 emulators look. On my 8.3 inch tablet they work well and easy to read. https://uploads.tapatalk-cdn.com/2016...6e9c36bf21.jpghttps://uploads.tapatalk-cdn.com/2016...3445ff7a04.jpg
Reply:Ok. I'll set a couple of searches up. See what happens. Sorry for thread hijackTiger Sales: AHP Distributor www.tigersalesco.comAHP200x; AHP 160ST; MM350P, Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma. For Sale: Cobra Mig 250 w/ Push-pull gun. Lincoln Wirematic 250
Reply:
Originally Posted by soutthpaw
I gotta buy one of those $100+ fancy calculators for my pre-calculus class this semester
sticks because I got a perfectly good Ti84/89 emulator on my tablet but the school won't let you use phone or tablet calculators for the tests. Sent from mobile. Not responsible for Typos
Reply:I usually draw it out on the welding table, then use a tape measure to get the length on the third side. Good luck
Reply:Hello Willie, one way to answer this question would be to: multiply 16.05 X 1/2 the angle of 17.1428571428 Sine, this will equal 2.392128372. Multiply this number by 2 and that will equal 4.784256743 which will be the length of your missing side. Your question describes the math generally required to determine a "chord" dimension. Best regards, AllanLast edited by aevald; 01-16-2016 at 09:50 PM.aevald
Reply:What's up with carrying 10 sig digits on an angle, when the legs have 2 sig digits. Why? Why?HP 15C. Non-graphic capability. It's been used to solve challenges around the globe.
"Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:I did it!!! It took me some time to keep trying it until it worked! The application is a crawler sprocket. The pitch of a track chain must match the pitch of the sprocket when new. They will never match again. As chain wears, pitch increases. Each pin grows farther from the next with wear. To grow with the growth of pitch, the sprocket gullets would have to become farther apart, The opposite happens. Gullets wear closer to the axle, track bushings wear, bringing the effective radius closer to the axle. In a well matched set all the sprocket teeth are pulling on the track chain. on a worn out set, only the first tooth pulls. All the others are slack on the sprocket. Wear is accelerated. In reverse, the tractor isn't holding the gullet on the bushing with its weight. Only the weight of the track opposes the natural tendency of the bushing to ride up to the tip of the tooth. The first bushing climbs mostly out of the gullet riding on the tooth tip, the second track bushing better engages the gullet to pull. A fellow with new SALT (sealed and lubricated tracks) chains on a Cat D3 has a chain popping problem. I believe the bushing diameter in the chain is larger than standard, giving an effectively larger radius to the sprocket. With larger radius, and equal teeth number, the sprocket pitch grows. The chain engages every other gullet. The angle between track pins is 720 degrees divided by the number of teeth because it takes two revolutions to engage all gullets.Thanks again everyoneDave, you've saved another struggling math student, thank you.WillieAn optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:Glad it worked out for you - sounds like an interesting repair
Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:I don't use trig much since I started using autocad Just draw triangle and pick unknown dimensions offdrawing. I do the same thing for bolt circles and othergeometric problems. Draft site is freeMiller a/c-d/c Thunderbolt XLMillermatic 180 Purox O/ASmith Littletorch O/AHobart Champion Elite
Reply:About the calculator issue: check if any of your math classrooms have any old calculators laying around. Believe it or not but a lot of seniors in my hs will just leave their calc after they graduate. Of questionable morality but where else are those calculators going to go?"I thank God for all the freedoms we've got in this country, I cherish even the right to burn the flag, but I'll tell you what, we've also got the right to bear arms and if you burn my flag I'll shoot you"-Johnny Cash
Reply:
Originally Posted by soutthpaw
Yeah, the school still teaches on ti84. It seems really bass ackwards design that is a 20+ year old interface. So much for using the latest technology. I'm thinking about the Ti Nspire CAS or the HP prime if you are familiar with either of those. I'm gonna ask the first day of class. See what the professor recommends or is familiar using. Sent from mobile. Not responsible for Typos
Reply:
Originally Posted by Ace86
Southpaw, just wanted to stick my 2 cents in. You should definitely get the calculator that the professor recommends. Some brands like to mess with the order of the key strokes to get the same thing done. It will play havoc on you when the professor is demonstrating some thing and say press "X" and your really needed to press "Y" then "X". I want to say that HP is guilty of this, but it has been almost 10 years and I could be wrong. It also really helps if you use the same calculator for 4 years. You start to know when there is a setting wrong; I don't know if the emulator is that exact that it replicates all of the setting screens. There is nothing worse then figuring out your calculator is in rads during a test but your can't find the setting to change it back. Anyway take it for what its worth.
Reply:I watched several videos on YouTube on both the 84 and the Nspire. Decided to order a Nspire on Amazon. Just seems much more intuitive. I can use the emulator on my tablet in class (emulator uses TI ROM so it's identical) to follow the lecture and just figure out the process on the Nspire with the homework.Tiger Sales: AHP Distributor www.tigersalesco.comAHP200x; AHP 160ST; MM350P, Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma. For Sale: Cobra Mig 250 w/ Push-pull gun. Lincoln Wirematic 250 I'm sure that combo will work just fine ☺Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Hello Willie. Two numbers you might be interested in . The square root of 2 and square root of 3 and how they apply to electricity. Its kind of calculus, statistics and trig IMO.The square root of two or 1.414 is used to find RMS of peak sin wave. Example : 122VAC RMS is actually 122 * 1.414 or 173 volts peak. The square root of three or 1.732 is used to find the combined voltage from 2 phases in a 3 phase system. Example: 230 volts (phase to neutral) times 1.732 equals 400 volts phase to phase.Hope you find this useless information interesting and maybee not useless someday.BTW, credit goes to OLDENDUM for making me aware that 1.414 is the square root of two from another thread.
Also useless and interesting, the HP calculator that Manoki mentioned is similar to what Apollo astronaughts used to navigate around the globe according to my old retired Airforce navigator bud.
Reply:While I know the definition of the three words root, mean, and squared, combined, I understand only to the degree that expensive meters give values RMS. I would however be delighted to understand. If I understand correctly the square root of three factors amperage, or wattage in a single conductor of a three phase circuit. 25000 watts single phase 240 volts is 104 amps. 25000 watts 240 Volts three phase is 104/1.73 or 60 amps on each conductor. Me wrapping my brain around the concept that three transformers can provide 300 amps single phase or 60 amps three phase wasn't easy.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:@ Willie B - the easiest way to think of RMS is that it represents an AC current required to produce the same heat as current in a DC circuit. AC voltage or current are commonly expressed as RMS values."Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:Root Mean Squared have been explained that way for the last 47 years to me. I think I once met a man who understood what it means, he was too busy that day to explain. An arbitrary number 16; Its root is 4. 4 squared is 16. Between 12 and 20 16 is the mean. Don't I still have 16? In AC, current is not always at peak RMS gives effective power.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:@ Willie B - if try to "think" graphically, this vid may aid in your quest for the truth. Integral (opposite of derivative) calculus is contained within the core this concept. Supplemental RMS Graphics for your viewing pleasure.Last edited by ManoKai; 01-19-2016 at 08:33 PM."Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:Mano; Thank you. a logical explanation. I'm still not getting why it isn't .5 of the Ac peak, but rather the square root of .5WillieAn optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:Because the square root of 0.5 = 0.707 or 70.7% of peak. 20 volts ac pk is 14.14 RMS.Good explanation Mano about the equivalent heat of a DC circuit. I think the true RMS meters use this instead of the square root of 2 for non sinusoidal waves. The square root of two doesnt work for square waves but then I hear mixed responses about that.120 vAC from utility company is actually around 170 v peak. On an oscilloscope you would read 170 AC pk.Last edited by Insaneride; 01-20-2016 at 10:04 AM.
Reply:Got my Nspire. Pretty intuitive interface. Much more so than the TI84 I have on the emulator. Downloaded a bunch of the exercises from the TI education store, slowly working through a few to find my way around better. I'll just go bug Insaneride if I get stuck.Almost went with the Casio CP400, but the lack of 3D graphing changed my mind.Tiger Sales: AHP Distributor www.tigersalesco.comAHP200x; AHP 160ST; MM350P, Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma. For Sale: Cobra Mig 250 w/ Push-pull gun. Lincoln Wirematic 250
Reply:I can loan you my TI85 Southpaw. I never heard of the Nspire till you mentioned it. In fact, I never new a TI 89 was out. The TI 86 had just come out whenever I took my last math class and the book we used didnt support it. Some smart guy in class bought one and he figured out how to get buy with it. Like MDave said, "you have to learn how it works instead of learning math with it". Or something like that. If you have problems, you can use my TI 85
Reply:i want to come and watch when you measure that angle between the to long sides. 10 decimal places? your good.
Reply:I have a TI-85, two TI-92 Plus', and a Nspire CX CAS. My fave by far is the 92 Plus, but then again. I haven't gotten my hands on a Voyage, which I think I will love.
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Reply:RMS is not an electrical; term though it is used in electricity. It is a mathematical term. Think of it as a fancy way to find a very accurate average or mean if you will. Instead of taking all of the data points, adding them together and then dividing that number by the number of data points, you take the square of each data point, add those together, divide that number by number of data points then find its square root it to achieve the answer. Example: average method----data points (27,29,24,27,27, 30, 30, 26, 28, 29, 27, 29, 31, 23, 26, 26, 29, 28) average/mean= 27.5556. using the RMS technique the answer would be: RMS 27.63049845 Only a slight difference but the RMS method is a more statistically accurate number. We used is all the time back in my machinist days to define how smooth a machined, ground or lapped surface was.
Reply:Side angle side: https://www.mathsisfun.com/algebra/t...triangles.htmlMiller Multimatic 255
Reply:
Originally Posted by MinnesotaDave
True, the TI-89 has all the same features, just hard to see the screen for me.In the past I've written several programs for the Voyage 200 when I needed them - they transfer directly to the 89 so I never understood why they allow one but not the other.
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Originally Posted by Oscar
Just revisiting this thread and saw this post. As a previous math teacher turned Testing Coordinator in charge of standardized state testing in my school, I can tell you that it has nothing to do with programs, it has to do with test security. Test security is a HUGE deal with state-mandated standardized testing. Granted that anything is possible, the probability of a student trying to copy/reveal/divulge the content of state testing on a calculator with a qwerty keyboard is much higher than on a calculator that doesn't have one, and this is a huge deal because the contents of such tests cannot under any circumstance be viewed by anyone who is not authorized to do so. A student's test, or that classroom's student's tests, or even an entire school's tests can be invalidated should any test content be leaked out. Granted there are measures that are supposed to be taken, such as clearing a calculator's entire RAM bank before-and-after testing, should someone miss this for whatever reason and test content is "snuck out", someone's gonna get written-up at best, or permanently lose their job at worst.
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Originally Posted by MinnesotaDave
Unless you work at the tribal school I finally got out of. Test security is not followed by many of the staff. Cell phones allowed during testing, unsupervised breaks with cell phones still in possession, hints given during tests....etc....No punitive measures, mostly people turn a blind eye because it's a tribal school where racism is constantly being claimed during any attempts at correcting the situation.Fake grades that lead to fake high school diplomas.Verbal, emotional, physical abuse of teachers and staff.etc, etc, etc...Employees are on a total non-disclosure. But I don't work there anymore...
Reply:
Originally Posted by Oscar
Things are much different 'round here. Here in Texas, the FBI will go after anyone suspected of tampering with such things, even years after the allegations if it merits.FBI arrests five in a Texas ISD test-rigging scandal orchestrated by ex-DISD officialA 15-Year-Old Was Arrested Today for Disrupting the STAAR TestDon't mess with Texas.
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发表于 2021-9-1 23:18:29