Mathematics

Help is needed, once more, in expressing these equations using proper algebra and proper nomenclature. The math seems to work ok, it just needs to be corrected for grammar and puctuation, so to speak. To try and avoid some confusion as to exactly what this topic is about, some new terminology is introduced in order to distinguish this technique from other, more standard, methods. The main addition is the term antivector. This is no different (mathematically) than a standard vector where the roles of length and direction have been reversed. Basically, this new terminology has been invented in order to help assure other members that this author understands what a st…

Hello, Here I share with you a paper I wrote on Selective Incompatibility in sets and an approach to the duality P vs NP. Paper link : https://­drive.google.com/­file/d/­0B2iY_1VArjmYTUttR1h5­WTRIWDg/­view?usp=drivesdk Regards

According to the Regional Bar​ Association, approximately 65​% of the people who take the bar exam to practice law in the region pass the exam. Find the approximate probability that at least 69​% of 500 randomly sampled people taking the bar exam will pass. Although I do want the answer, how do I actually get it?

Numbers are amazing ,if we deep study about we get a lot miracle which we have to bring out ,in this view one more article see and observe why is it so……….why always 6. (2,2,3....2,2,3......) 123-----1+2+3=6=0+6=6 456-----4+5+6=15=1+5=6 789-----7+8+9=24=2+4=6 101112----10+11+12=33=3+3=6 131415-----13+14+15=42=4+2=6 161718-----16+17+18=51=5+1=6 192021-------19+20+21=60=6+0=6 222324------22+23+24=69=15=1+5=6 252627------25+26+27=78=7+8=15=1+5=6 282930-----28+29+30=87=8+7=15=1+5=6 313233------31+32+33=96=9+6=15=1+5=6 343536------34+35+36=105=1+0+5=6 373839------37+38+39=114=1+1+4=6 404142------40+41+42=123=1+2+3=6 434445------43+44+45=132=1+3+2=6 464748-…

Hello I was wondering: when you use a parametric test on data (e.g. unpaired Student's t-test), you may report a certain t(df), and p value, and you may report mean and a certain confidence interval to give an idea of the direction of the (in)significance or the trend of the result. But what when you get to use a nonparametric test? Let's say you use the nonparametric equivalent of the Student's t-test mentioned above: the Mann-Whitney U test. What will you report? I may recall incorrectly that nonparametric tests are based on the median and IQR, rather than on means and CIs. Then again, I might recall correctly that they are based on (mean) ranks ... So let's…

Hi, I'm currently reading through Universal: A Guide to the Cosmos by Brian Cox and Jeff Forshaw and have a question related to one of the calculations detailed therein. The calculation specifically is to do with the use of isochron plots for dating rock samples using the decay of 87Rb into 87Sr. An example of this kind of isochron is attached. Now the passage in the text says that if g = the fraction of 87Rb that has decayed since the rock was formed, then the tangent of the tilt of the line is given by g/(1-g). The text then goes on to determine the value of g by determining the slope, which in this particular example is given by (0.7325-0.699)/0.5 = delta-y/del…

Hi, I'm trying to understand why when a point belongs to a straight line the epura looks like this, in this case (A, B and C are the points) (R,T and (EF) are the lines) Sorry eventual english mistakes

I'm using the book Calculus, 6th Edition (Stewart's Calculus Series), and I'm having some trouble to figure out why he calculates the difference between two integrals to find the area between then. It's ok for me to understand when the y values of both functions are positive. But when one of the y values in one of the functions is negative he uses the same formula (integral of A) - (integral of B) {A and B are two functions}! What about that rule that when the y value of the function is negative the integral is also negative?

Hello everyone Quick one; I don't seem to find what is preferred in reporting statistics: mean (SD) or mean (95 % CI)? Basically one can be calculated from the other, so it shouldn't matter too much, but what is more commonly used or favourable? Thanks. F

In a Right angle triangle ABC AB=3,AC=4 & BC=5 at BC,E is middle point and D is altitude AD Find distance DE=? it is not a difficult question eveyone who know maths can solve easly but question is solve it in one line...........

f(x) is a ploynomial such that f(1)=3, f(2)=3, f(3)=6, f(4)=1,f(5)=4, f(6)=6, f(7)=2, f(8)=5, f(9)=0, f(10)=3, f(11)=5, f(12)=1.Find the equation of x, i.e. f(x).

I have a problem remembering the right maths to use for a technical problem I am trying to solve. Is there anyone here that can point me in the right direction please? Here is the problem; Lets say there is a population of 1,000,000 people Within this population I want to know what percentage have a certain condition. The proportion of people who have this condition is likely to be in the range of circa 1 in 75. Lets assume that the people with the condition are distributed randomly distributed across the one million population I would like to work out the number of people I would need to sample to know with a degree of certainty what proportion of people…

take the inverse of 16 add 7 take the inverse of that add 3 or consider using only inverse (dividing 1 by the number) multiplication, addition and the numbers 2 and 3. Simple as 1 2 3 take the inverse of 2 times 2 times 2 times 2 add 2 times 2 plus 3 take the inverse of that add 3 3.1415929203539823008849557522124 is close enough to 3.141592653589973238462643383279 for a lot of purposes. So if you forget 355/113 and want that exact approximation, to 6 digits, just take 16 inverse it, add 7, and inverse that, and add 3.

Hi, I need to derive a formula for the moment of resistance W (x), at a distance x from the left bearing. This W (x) satisfies the formula: W(x)= b(x)^3 / 6 Given: applies for a rectangular cross-section: W= b*h^2 The function b (x) : b(x) = b(l) + ((l-x)/l)* (b(0)-b(l)) How do I do this?

I've read that some believe that Phidias, whose name was given to the Golden Ratio Phi, was the first to use the ratio in his sculptures, others say it goes further back in history to the Summerians. It appears frequently in nature,but, what causes it's existence?

Dear all, I have a problem with comparing two lower confidence intervals of odds ratio. The detail is follow: I have: lci1 = e^[ln(a*d/b*c)-1.96*square root(1/a+1/b+1/c+1/d)] lci2 = e^[ln(a*(d-1)/b*(c+1) - 1.96*square root(1/a+1/b+1/(c+1)+1/(d-1)] I want to approve lci1 > lci2 with all 0 < a,b,c,d < N I have progammed this problem in computer. As the result, it is true ( lci1 > lci2 ). We want demonstrate this inequation in mathematisc style. Could you please help me? Thank you in advance! Best,

I also posted the following in the sci.math newsgroup but got no responses that actually were interested in the main point of the "discovery" i thought i made. would be happy if somewhere here could find the time to actually fill in the sieve of numbers as i am illustrating below: Sieve of Vic? I think i have discovered a more beautifull way to find the prime numbers by using a Sieve. But i might be mistaken and have rediscovered the wheel. My prime finding sieve method shows the iterative nature of the primes very well and is therefore intriguing. In short each primes causes an infinite number of other numbers to be composite-numbers, but the composite numb…

So, I was looking into fields and was studying up on them, and noticed that associativity seems to be a rephrased version of commutavity. For a set [latex]S[/latex], with operations [latex]*[/latex] and [latex]o[/latex], and given that the set is commutative, but not necessarily associative, we can rephrase the question of associativity like so: [latex] a * (b * c) = (a * b) * c \implies (b * c) * a = (a * b) * c \implies (b * c) * a = (b * a) * c [/latex] This is rather obvious, especially if it is associative, but we can still phrase it differently: For a given [latex] b [/latex], where [latex] x|y = (b * x) * y [/latex], is [latex] | [/latex] commutativ…

Suppose you are given the relation that [math] a^a= b [/math] . Then how you do you proceed to find a in terms of b ? Or, the solution doesn't exist.

(Disclaimer I am a very curious 14 year old so bare with me) I found an article saying glass with 2.5 g/cc would have to be 14 light minutes(Lm) in radius to create a black hole, I am now trying to find out how many Earths' that would have to be in a row to create a black hole. I just need help with the math. Would this mean 1 g/cc would have to be 23.333 light minutes(Lm) large to create a black hole considering 14Lm + (14Lm ÷ 1.5g/cc) = 23.333Lm/g/cc (Lm being Light Minutes)? 1 g/cc density would take 23.333Lm to make a black hole ? Considering this that would mean Earth (Which all together has a density of 5.513 g/cc) would be 5.513 g/cc 5.513 g…

From that other thread I wondered "hmm, how would I come up with that from scratch?" How would you go from a simple recursive series to that exponential formula? http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Fibonacci/fibFormula.html#section1

Is there a quick and easy way of working out the nth number in the Fibonacci sequence when you don't know the values of the two preceeding numbers in the sequence?

For some reason I just literally can not figure this out, my brain has hit a wall even though I know it's so simple... So I have 25,000mg of binder and I have 250mg of active ingredient. All I need to know is what is the ratio, how do I figure out how much active ingredient is in x amount. Lets assume I wanted like 3 mg worth of active ingredient, how much would I have to scoop from the mixture to get that?

I think I have my own methodology but I'm curious to see what the formal definition of this is. I'm looking for an x-value of a function where its integral is the same on both sides of the x-value over some interval [a,b]. With some testing it doesn't seem like the average value theorem directly relates to the answer, but it seems like the general answer should be something close to that. The answer I got is [math]x=F^{-1}(\frac{F(a)+F(b)}{2})[/math] where F(x) is the integral of f(x).

So what I thought I knew years ago for some reason I am confused with right now. How shameful! Wonder which marble I lost? I must have had a brain fart. Anyway, the identity goes (a - b)2 = a2 + b2 - 2ab Going from right to left, without knowing the left side, how would we know whether the negative term is a or b?