Recent content by Mr Davis 97

  1. Mr Davis 97

    Dimension of set of all linear maps that map three elements to zero

    Sorry, ##a = \operatorname{dim} V## and ##b = \operatorname{dim} W##. And yeah, I actually did that and I think I was able to solve it in that case. Basically, if we're trying to find the dimension of ##\{ T\in \mathrm{Hom}(V,W) : T(v_1) = 0 \}##, where ##v_1## is nonzero, then if we define...
  2. Mr Davis 97

    Dimension of set of all linear maps that map three elements to zero

  3. Mr Davis 97

    Help with picking out which point has the most negative derivative

    But I guess what I'm saying is that wouldn't this problem restrict itself to the interval ##[0.5, 5]## because that's all we're given?
  4. Mr Davis 97

    Help with picking out which point has the most negative derivative

    All we're given is that y = f(x). We don't know what kind of function it is. And it probably isn't ##-\infty## because that seems too complex for the nature of the question.
  5. Mr Davis 97

    Algebra word problem about planning a concert

    This seems like a simple problem, but I am a little confused by a few things. For one, what is the use of the piece of information that when they charged $100 per person they got 3000 people to come? Also, how should I proceed with the information "for every $2 decrease in price they would have...
  6. Mr Davis 97

    I Trying to understand terms in a problem

    Any hints? I feel for someones who knows topology this would be an easy problem
  7. Mr Davis 97

    Sum of sides of n polygons in quadrilateral is no more than 4n

    A line in this case is a segment from one side of the quadrilateral to the other. Here is the problem I am actually trying to solve: Let ##Q## be a convex quadrilateral which is cut into convex pieces (cells) by a finite number of lines. For any collection ##(Q_i)_1^n## of these cells...
  8. Mr Davis 97

    Sum of sides of n polygons in quadrilateral is no more than 4n

    I can construct examples that are less than or equal to ##4n## quite easily, but for the life of me I cannot come with example where it's greater than
  9. Mr Davis 97

    I Trying to understand terms in a problem

    A convex disc is any compact, convex set with non-empty interior
  10. Mr Davis 97

    I Trying to understand terms in a problem

    So as someone who has a limited understanding of topology, what would be a hint or a first step for this?
  11. Mr Davis 97

    I Trying to understand terms in a problem

    Here is the problem: Let ##C## be a convex disc in the plane, and ##C_1## and ##C_2## be two translates of ##C##. Prove that ##C_1## and ##C_2## are non-crossing, that is, it isn't possible that both ##C_1 - C_2## and ##C_2 - C_1## are non-connected. Here is my question: What exactly do the...
  12. Mr Davis 97

    I How Does Scaling Affect the Coordinates of a Rectangle in the Plane?

    This is a pretty simple question, I am just trying to clear up confusion. Let ##D## be the rectangle in the plane with vertices ##(-1,0),(-1,1),(1,1),(1,0)##. Let ##\lambda >0##. Then what exactly does the set ##\lambda D## look like? Is it correct to say that, for example, ##2D## is the...
  13. Mr Davis 97

    I Why do I get two different values for an integral?

    Suppose ##t \ge 0##. Let ##\displaystyle I(t) = \int_{-\infty}^{\infty}\frac{x \sin (tx)}{x^2+1}~\text{dx}##. Call this form 1. Note that we can also write the integral as $$ \begin{align*} I(t) &= \int_{-\infty}^{\infty}\frac{x \sin (tx)}{x^2+1}~\text{dx} \\ &=...
  14. Mr Davis 97

    I What are the properties of a plane cut into regions by a set of lines?

    Problem: Let ##L## be a set of ##n## lines in the plane in general position, that is, no three of them containing the same point. The lines of ##L## cut the plane into ##k## regions. Prove by induction on ##n## that this subdivision of the plane has ##\binom{n}{2}## vertices, ##n^2## edges, and...
Back
Top