1. math951

    Reference angles question (confusion on my part)

    Let us say find cosine 230 do I always subtract it from 270? Or would I do 230-180. It looks like on my notes I did it sometimes from both ways which way is the correct way? For instance I had a problem where I had sin being 15.5 but it was also 165.5 why wasn't it just 105.5??? Because on my...
  2. J

    Looking for book on ZFC axiomatic set theory

    I am looking for a book that starts at the standard ZFC axioms and progresses to the point where some recognisable non-trivial mathematical statement is proved. By recognisable I mean something that you may encounter in school/early university level and is not purely set-theoretical (e.g...
  3. R

    Check all that apply. π/4 is the reference angle for:

    Check all that apply. π/4 is the reference angle for: A. 19π/4 B. 12π/4 C. 7π/4 D. 15π/4 I just want to check from my calculations the answers would be A., C. and D. Not B. (12π/4) because I think that the reference angle is 3π radians. Please let me know. Thank you!
  4. J

    Good reference on multi-variable calculus of variation

    I am looking for a good and easy access reference on multi-variable calculus of variation with many examples and demonstrations. Although I have many books and references on the calculus of variation, most are focused on single-variable. Any advice will be appreciated.
  5. S

    Looking for a reference for advanced probability distributions

    Hello all, I am looking for a reliable reference which gives the basic properties of as many standard distributions as possible. I have tried google and wikipedia with no luck. By "basic properties" i mean things like: PDF CDF MGF Mean, Variance Skewness, Kurtosis, etc The maximum likelihood...
  6. L

    How to calculate the reference of numbers?

    Is there anyway to calculate the following? As you can see when the first number increases the 2nd number only increases a little bit. I would like to calculate the other numbers with the same reference. Thanks 6.6162 = 2.598 11.2262 = 2.939 9.2362 = ? ( I know is around 2.7 something) 4.9068...
  7. S

    Retired Statistician Selling My SAGE Statistical Reference Book Series - 25 Books !!

    Dear Fellow Statisticians, I hope this will be considered and appropriate post by the Admins. I'm a retired life-long Statistician and Researcher that wants to see my SAGE University Series (the Green Applications Paperbacks) containing 25 Popular Titles i.e., 25 books, "go" to a good home...
  8. M

    Frobenius Theorem (reference)

    Hi, I'm looking for a nice reference on the Frobenius Theorem. Ideally, I'd like to find a reference that's going into detail on its various forms (vector fields/differential forms) and has a lengthy discussion on applications in PDE theory. I'm currently using Lee's Smooth Manifolds book...
  9. D

    Trouble finding reference angles with radians

    I am having trouble finding reference angles with radians. For instance: #1) 33pi/4 #2) -23pi/6 How do I go about solving these?
  10. L

    Frame of reference question. Polar co-ordinates

    A lighthouse keeper spots a ship sailing away from the shore. She marks the bearing from North to the ship as \theta=24 degrees and estimates the distance to the ship as 2.4km. The captain of the ship notes the ship is heading \phi = 30 degrees from north. If the captain similarly estimates...
  11. vaironxxrd

    Finding Reference Angle

    Hello again and again Everyone, I'm having trouble finding a reference angle for the following angle. \theta = -1.8 The book provides me with the answer which is \theta' \approx 1.342 But I cannot reach it, through my procedures. I know the following is WRONG. But I'm trying to layout my...
  12. S

    Reference or explanation of zeta mellin transform in critical strip

    Hi. In Apostol's book "Introduction to analytic number theory", Teorem 3.2(b), Apostol proves (1) \zeta (s) = \lim\limits_{x \to \infty} \left\{ \sum\limits_{n \leq x} \frac{1}{n^s} - \frac{x^{1-s}}{1-s} \right\} for s in critical strip. I know this translates to a Mellin transform integral...
  13. P

    Finding a reference angle and a trig function

    I am asked: tan(315^0) = -1 Find the reference angle and trigonometric functions for cosecant0 and secant0 I think this has something to do with the 4 quadrants on the graph, but I forget how to apply it to this question. Thanks!
  14. D

    Trigonometry questions involving multiple topics

    Math is definitely NOT my subject & my "teacher" CAN'T teach. So some help would be amazing! Here are some example questions I want to understand: 1. How do you find the reference angles for: -190° -3π/4 5π/8 2. Are the following true or false & why? cos(-175°) = cos(175°) cos(32°)...
  15. S

    Need a reference card for algebra and basic math rules

    I need a quick reference to math rules that I can refer to when solving algebra and other math problems. When I'm working on algebra problems I find myself having to do google searches for rules on algebra and rules on math that I need to perform while working on algebra problems. Anyone have...
  16. F

    Question about rotation and reference

    Hi. Let's suppose to have a car with a reference system called Body-NED with its origin in the center of gravity of the car, Xb-axis (called North) pointing towards the front of the car, Yb-axis (called East) pointing towards the right door and Zb-axis (called Down) pointing...down the street...
  17. M

    Find point of deviation from reference

    Hi, I have a set of reference values. After a particular experiment I get a set of result. How can I identify a point after which it deviated above a threshold value? An example: suppose the reference is 20,19,18,17,16,15,14,13,12,11. After an experiment the values are changed to ...
  18. Y

    Reference for a derivation of the multidimensional integration by parts formula

    The general integration by parts formula in multiple dimensions is given by \int_{\Omega} \nabla u \cdot \mathbf{v} = \int_{\partial\Omega} (u \mathbf{v})\cdot n-\int_\Omega u \nabla\cdot\mathbf{v} Is there a good reference that details the derivation of this formula? More specifically, I'm...
  19. M

    Book reference?

    I'm looking for a book (or books) with an introduction to Clifford Algebra, preferably with the build up of the Clifford Algebra through Tensor spaces. Also need information on the Dirac operator (in Cln), and maybe some uses in applications would be nice (though not needed). My local...
  20. G

    Function to find the ratio of a reference value given a low and high limit

    Hi all, I am just looking for the generic name of a mathematical function that will return the ratio of a reference value between a supplied low and high limit. This is probably best illustrated by example: 1st value is reference, second value is low, and third value is high SomeFunction(5, 0...