Recent content by ILikePizza

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    Proving Continuity and Linearity of a Function

    Homework Statement Given that f(x + y) = f(x) + f(y), prove that (a) if this function is continuous at some point p, then it is continuous everywhere (b) this function is linear if f(1) is continuous. Homework Equations definition of continuity The Attempt at a Solution (a) I...
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    Proving the Convergence of (y_n) Given a Properly Divergent Sequence (x_n)

    Homework Statement Suppose that (x_n) is a properly divergent sequence, and suppose that (x_n) is unbounded above. Suppose that there exists a sequence (y_n) such that limit (x_n * y_n) exists. Prove that (y_n) ===> 0. Homework Equations (x_n) ===> 0 <====> (1/x_n) ===> 0...
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    Another proof of limit by definition

    So x-c = \delta, and x2+ cx+ c2 --> 3c^2. So if \delta = \frac{\epsilon}{3c^2}, that's good. But how do I write this rigorously? Thanks again
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    Another proof of limit by definition

    Homework Statement Prove that as x --> c, lim (x^2) = (c^2) using only the definition. What does this tell you about x --> c, lim (x^3) = (c^3)? x --> c, lim (x^4) = (c^4) ? Prove it. Homework Equations The definition of a limit. The Attempt at a Solution Let $\epsilon > 0$ be...
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    Proving Divergence of (x_n): A Homework Challenge

    L+1/L = x_n = L x _n+1 > L, a contradiction? Is that what you were fishing for?
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    Proving Divergence of (x_n): A Homework Challenge

    Thanks for the reply. I am aware that this will work, but I still have no idea where to start. It is easy to show that this sequence is monotone increasing, but what about the second part? That's where I'm stuck. Thanks
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    Proving Divergence of (x_n): A Homework Challenge

    Homework Statement (x_n) is a sequence and x_1 > 2. From then on, x_{n+1} = x_n + 1/x_n Prove that (x_n) is divergent. Homework Equations n/a The Attempt at a Solution I first tried assuming that a limit existed, but I didn't get a contradiction. (I had x = 2 + 1/x, x = (2 \pm...
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    Is 1.230000... Equal to 1.230000...?

    I don't think you guys are reading what i said... I now *know* that .9999 = 1, but my question is: "I guess that my real question is that if a1.a2a3a4...aN = d1.d2d3d4...bN (finite number of digits) then all the corresponding digits are the same." Is this true or not? Do you have a proof?
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    Is 1.230000... Equal to 1.230000...?

    So, Friday in class, my teacher was talking about how .99999... = 1.00000... So, this makes sense and all, but this is my question: How do you know that 1.230000... = 1.230000...? I guess that my real question is that if a1.a2a3a4...aN = d1.d2d3d4...bN (finite number of digits) then...
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