Recent content by logan3

  1. L

    MHB H and * Problems in Epp's Book

    I emailed the author. She said that the meaning of these two symbols were placed only under the first Exercise Set of each Chapter, rather than in the Preface. "Appendix B contains either full or partial solutions to all exercises with blue numbers. When the solution is not complete, the...
  2. L

    MHB H and * Problems in Epp's Book

    I do understand what context means. However, you don't understand how to be polite. So I won't further respond to your posts.
  3. L

    MHB H and * Problems in Epp's Book

    The context is stated in the opening post.
  4. L

    MHB H and * Problems in Epp's Book

    Maybe it's explained somewhere in her book, but what do the Hs and *s mean beside some of the problems in Epp's Discrete Math, 4E textbook? Are there any other notations I should make note of in the book as well? Thank-you for your help.
  5. L

    MHB What's the use of subtangent and subnormal lines?

    What would be the point of knowing information about the subtangent and subnormal lines? Do they have any worthwhile real-world applications? Wikipedia says that they are archaic and fell into disuse after the early 20th century. Thank-you
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    MHB Proving a Set Theory Statement Regarding Families of Sets

    I was wondering if anyone could please check my work and reasoning for this problem. Thank-you! (Also, would this be considered a direct proof? How might a contradiction and IFF proof look like and compare?) Problem: Suppose F, G1 and G2 are nonempty families of sets. Prove that if F ⊆ G1 ∩ G2...
  7. L

    B Continuous but Not Differentiable

    Suppose a certain function in continuous at c and (c. f(c)) exists, then which of the two could be false: \displaystyle \lim_{x \rightarrow c^-} {f(x)} = \lim_{x \rightarrow c^+} {f(x)}, and \displaystyle f'(c)? I feel like both could be false, because if the formal derivative at a point...
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    MHB Group Theory: Proving Finite Rank of Torsion-free Abelian Groups Using Independence

    If someone can check this, it would be appreciated. (Maybe it can submitted for a POTW afterwards.) Thank-you. PROBLEM Prove that if $H$ and $K$ are torsion-free groups of finite rank $m$ and $n$ respectively, then $G = H \oplus K$ is of rank $m + n$. SOLUTION Let $h_1, ..., h_m$ and $k_1...
  9. L

    MHB Black Plastic Lid - Measurement Ratio

    Hi shamieh, I'm not quite sure what your post is asking, but as greg1313 pointed out $\pi$ is defined as the circumference of a circle divided by the diameter of the circle. If you were to measure these lengths with increasing accuracy, then you would get closer and closer to the value of $\pi$...
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    Testing GRE Physics Subject Test Course Equivalents

    I'm trying to make a check list of courses I need to study and review for the GRE Physics Subject Test. I have a few questions following the list. Thank-you for any help. Engineering Physics I Engineering Physics II Modern Physics Electricity & Magnetism Statistical Mechanics & Thermodynamics...
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    Find an Equation of the Tangent Lines Passing Through a Poin

    Homework Statement Find an equation of the tangent lines [in point-slope form] to the hyperbola x^2 + y^2 = 16 that pass through the point (2, -2). Homework Equations Point-slope form: y - y_1 = m(x - x_1) Slope: m = \frac {y_1 - y_0} {x_1 - x_0} The Attempt at a Solution First, take the...
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    Solve Basic Vector Problem: Resultant & Angle \alpha

    Homework Statement In a plane, find the resultant of a 300-N force at 30^o and a -250-N force at 90^o. Also, find the angle \alpha between the resultant and the y axis. Homework Equations x = F cos \theta y = F sin \theta r^2 = x^2 + y^2 \theta = tan^{-1} (\frac {y} {x}) The Attempt at a...
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    Tips for Tutoring Math: From College Algebra to Differential Equations

    I just want to say that if you just stick with tutoring these classes to students at your school, then you'll probably be fine. ...But once you start tutoring it to a wider range of students at different schools, then you'll have to develop a deeper understanding of the material. Because you'll...
  14. L

    What's the General Solution to This IVP?

    \frac {dy}{dt} = y^3 + t^2, y(0) = 0 My teacher said this IVP couldn't be expressed in terms of functions we commonly know. I was wondering what the general solution is? Thank-you
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    Finding Circle Circumference from Inscribed N-Sided Polygen

    I don't understand, sorry. But it seems like my thoughts about this relationship were in the right direction.
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