# Recent content by Barbados_Slim

1. ### Schools Applying to Grad School with no research experience

I'm a domestic student planning on applying to PhD programs in physics this fall but I am concerned with my lack of research experience. I realize this is an odd position to be in but I'm deeply interested in physics and think I'm an otherwise good candidate for graduate study. I'm interested in...
2. ### Power Series Solution of Differential Equation

Ok this made a lot of sense. Thank you both very much.
3. ### Power Series Solution of Differential Equation

Sorry I'm still confused. I got the series you got for the y' term and then I changed it to \sum^{\infty}_{n=2}(n-1)a_{n-1}x^{n} so I could combine it with the other sum, which I rewrote as a_{0}+a_{1}x+\sum^{\infty}_{n=2}a_{n}x^{n}. Normally I would set all coefficients equal to zero and then...
4. ### Power Series Solution of Differential Equation

I have edited the write up to hopefully make it more clear
5. ### Power Series Solution of Differential Equation

Homework Statement (x^2)y' = y Homework Equations The Attempt at a Solution Plugging in series everywhere I get the equation \sum na_{n}x^{n+1} = \sum a_{n}x^{n}. I try to set the coefficients for the corresponding powers equal, but when I do I don't get the correct answer. I also...
6. ### Determining the Height of a Building

Homework Statement You are sitting by a window when someone on the roof drops a ball. The ball spends .30 seconds in front of the window (which is 1.50 meters tall.) The ball subsequently hits the sidewalk and bounces back up at the same speed. On its way up it passes by the window again...
7. ### Sum of an infinite series

I was doing my math homework when I started thinking about the sums of two infinite series. I determined that the sum of the first series \sum_{n=1}^{\infty} cos(\frac{\pi}{2n}) diverges. I could not figure out whether or not the series \sum_{n=1}^{\infty} sin(\frac{\pi}{2n}) converges or...
8. ### Find the vertical asymptotes of the graph of the function

Thank you for your help.
9. ### Find the vertical asymptotes of the graph of the function

Is it because the limit as x approaches 0 is 1?
10. ### Find the vertical asymptotes of the graph of the function

Homework Statement Find the vertical asymptotes of the graph of the function. (Use n as an arbitrary integer) \frac{tanx}{x} Homework Equations N/A The Attempt at a Solution I believe the answer is x=\frac{\pi(2n+1)}{2}. I would just like somebody to confirm or deny this. Thanks...
11. ### Mathematical Induction Proof

Homework Statement Prove that 11^n - 4^n is a multiple of 7 Homework Equations N/A The Attempt at a Solution I substituted k+1 in for n and simplified to get 11(11^k)-4(4^k) but after this point I get stuck. Any help would be appreciated.
12. ### Questions about sequences

I figured out the problem with the telescoping series. I was just using the wrong letter, I used "k" instead of "n". As for the other problem about the boundedness. I believe that boundedness refers to certain values that the sequence never gets larger or smaller than, like jhae2.718 said. The...
13. ### Trigonometry Function Help

Rewrite the second function y=sin(x+90) using the double angle formula sin (\alpha + \beta) = sin {\alpha}cos {\beta} + cos {\alpha}sin {\beta} Then the answer to part one of your question should become apparent.
14. ### Questions about sequences

Well thank you for your prompt answer. I hope you don't mind but I have another question. \sum_{k=1}^{\infty} \frac {1} {k(k+1)} is an example of a telescoping series. Find a a formula for the general term S_n of the sequence of partial sums. I've reached the conclusion that the formula...
15. ### Questions about sequences

Homework Statement Determine whether the sequence with the given nth term is monotonic. Find the boundedness of the sequence. a_n = ne^{-n/2} Homework Equations I don't know The Attempt at a Solution I have absolutely no idea what a monotonic sequence is or how to find the...