Recent content by Born

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    Help with Apostol's "Calculus, vol. 1", Section 1.18

    I get what you're saying. The only problem is that Apostol still hasn't mentioned sequences. The only relevant thing I can think of that has been covered in the book till now is the Least Upper Bound Property of Numbers. Which would simply state that ##f(x)## is the supremum for ##Q'##
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    Help with Apostol's "Calculus, vol. 1", Section 1.18

    RUber, I see what you're saying, however the new step regions (S' and T') would produce functions bearing the following relationship with the function##f(x)##: ##s'(x) < f(x) \le t'(x)##. Which doesn't help since the definition of the integral requires "##\le##" for both step function...
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    Help with Apostol's "Calculus, vol. 1", Section 1.18

    In section 1.18 ("The area of an ordinate set expressed as an integral"), Apostol proves two theorems. the first, theorem 1.10, deals with the area of a function's ordinate set; the second, theorem 1.11, deals with the area of the graph of the function of theorem 1.10. (I have attached two...
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    Isosceles Triangles with Congruent Lateral Sides

    Yes, that makes sense. However, what I want to pove is that if the base and height of a right triangle are inside another then the hypotenuses cannot be congruent. If I can prove that then the isosceles triangles can be argumented to be case of two pairs of juxtaposed right triangles
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    Isosceles Triangles with Congruent Lateral Sides

    I just uploaded a picture to make it clearer.
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    Isosceles Triangles with Congruent Lateral Sides

    Homework Statement Problem 99 from "Kiselev's Geometry Book I - Planimetry": Two isosceles triangles with a common vertex and congruent lateral sides cannot fit one inside the other. Homework EquationsThe Attempt at a Solution The statement is obviously true. If we visualize each isosceles...
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    Do Quadrilateral Diagonals Always Remain Inside or Outside?

    ##\mathrm{Follow\ up:}## Concerning the pentagon: labeling the five vertex points A, B, C, D, E; and forming the sides AB, BC, CD, DE, and EA. A diagonal is made from point A to point D crossing the side BC. This is possible since the diagonal would only share one point with the side BC- (This...
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    Do Quadrilateral Diagonals Always Remain Inside or Outside?

    Simon, MidgetDwarf, and lurflurf, I think you'll like what I've come up with. I'm sorry to not be able to show some pictures but I believe the written proof will suffice. Hope it's clear enough. Thank you for your help. The three properties of straight lines in the proof are the following: (1)...
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    Do Quadrilateral Diagonals Always Remain Inside or Outside?

    Homework Statement Problem 55 from Kiselevś Geometry - Book I. Planimetry: "Prove that each diagonal of a quadrilateral either lies entirely in its interior, or entirely in its exterior. Give an example of a pentagon for which this is false." Homework EquationsThe Attempt at a Solution The...
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    What Is the Maximum Force on the Upper Block to Prevent Slipping?

    Homework Statement Kleppner and Kolenkow "An Introduction to Mechanics (2nd ed.)" prob. 3.2: Mass MA = 4 kg rests on top of mass MB = 5 kg that rests on a frictionless table. The coefficient of friction between the two blocks is such that the blocks just start to slip when the horizontal...
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    Solving a Pole-Leaning Problem with Negligible Mass

    Wow total brain fart. ##\ddot{y}=g\cos^2(\theta)## NOT: ##\ddot{y}= g \cos(\theta)## Therefore ##\ddot{x}=g\sin(\theta)\cos(\theta)=\frac{g\sin(2\theta)}{2}## So, I'm back were I started. The way the equation behaves is pretty interesting though, with a max value of ##\frac{1}{2}##, it starts...
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    How many elements are in a set of unique rational numbers from 1 to 9?

    Sorry, edited the mistake. The question would be; is there a simpler (and more elegant) way to count the number of elements in the set?
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    How many elements are in a set of unique rational numbers from 1 to 9?

    Let ##T = \{ \frac{n}{m}\in \mathbb{Q} \vert n, m \in \{ 1, 2, ..., 9 \} \}## No values can repeat (e.g. ##\frac{2}{2},\frac{3}{3},...##) How many elements does the set have. I could just go ahead and count the elements and eliminate the repeats, but I'm wondering if there is a simpler (and...
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    Solving for Acceleration in a Pulley System

    So I think this post is dead but I'll give it a shot and try to revive it. I'm sorry if it seems inappropriate but I must also check my answer to this problem Here is my my analysis: ##2T+N_{scaffold}-M_{parinter}g=M_{painter}a_{painter}##...
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