# Recent content by physicsernaw

1. ### Infinite series problem

Ahh I see thanks for clarifying. I will reattempt the problem. EDIT: Got it by simply using integral test from n=3 to infinity. The integral converges so the series must as well. Thanks LCKurtz.
2. ### Infinite series problem

The denominator is the first one you posted, n*(ln(n))^2 - n. In my book for the Limit Comparison Test it states "Let a[n] and b[n] be positive sequences." I assumed that "positive sequences" meant positive for all n [1, infinity). So it is really saying that if the sequence converges to a...
3. ### Infinite series problem

Homework Statement Determine convergence or divergence using any method covered so far*: Ʃ(1/(n*ln(n)^2 - n)) from n = 1 to infinity *The methods are the following: - Dichotomy for positive series (if the partial sums are bounded above and the series is positive, the series converges) -...
4. ### Integration along y axis

Verbatim: "In Exercises 27-44, sketch the region enclosed by the curves and compute its area as an integral along the x- or y-axis." ... 28). y = x^2 - 6, y = 6 - x^3, y-axis
5. ### Integration along y axis

Homework Statement Compute the area as an integral along the y-axis: f(x) = x^2 - 6, g(x) = 6 - x^3 Homework Equations N/A The Attempt at a Solution I solve for x in terms of y for both equations and end up with: f(y) = +/-√(y+6), g(y) = (6-y)^(1/3) I then look for interception points...
6. ### Doubling time problem

Ahhh, thank you so much.
7. ### First order linear differential equation

Homework Statement dy/dt = k*y*ln(y/M), where M and k are constants. Show that y = Meaekt satisfies the above equation for any constant a. Homework Equations y' = ky y = P0ekt The Attempt at a Solution Taking the derivative of y, I get: (Meaekt)*(aekt)*k which is, ky*aekt ..and I'm...
8. ### Doubling time problem

Homework Statement The only functions with a constant doubling time are the exponential functions P0ekt with k > 0. Show that the doubling time of linear function f(t) = a(t) + b at time t0 is t0 + b/a. Homework Equations n/a The Attempt at a Solution With initial time t0, P = at0 + b At...
9. ### Absolute value integral

Homework Statement ∫0-->x |t|dt Homework Equations // The Attempt at a Solution 1/2*x^2 for x>= 0 1/2*(-x)^2 for x<= 0 Not sure what to do to be honest. (the answer in the back of the book says 1/2*x|x|).
10. ### Computer Science or Electrical/Computer Engineering?

Unfortunately that is not available to me unless I double majored, but the CS degree and ECE degree have a good amount of overlap so getting a minor in CS would be easy.
11. ### Computer Science or Electrical/Computer Engineering?

After doing some research, those huge layoffs to engineers in the past few years (even recently Boeing and HP layed off thousands of engineers) due to offshoring makes me lean towards CS, but I've also heard the same applies to CS, although job growth for software engineers is pretty high as the...
12. ### Computer Science or Electrical/Computer Engineering?

Given that I am interested in both fields, which degree would give me the most job options after graduation (the degree is ECE, electrical and computer engineering)? For example, do employers consider applicants with an EE/CE (or in my case, ECE) degree when hiring software developers, or do...
13. ### Optimization problem using derivatives

I would have never thought of doing it in that way.. Thanks for the insight and taking the time to help me..
14. ### Optimization problem using derivatives

Here's what I got taking the derivative of the surface area, substituting h = 300/(pi*r^2) and l = sqrt(r^2 + (300/(pi*r^2))^2) SA(r) = pi*r*sqrt(r^2 + (300/(pi*r^2))^2) dSA/dr =...
15. ### Optimization problem using derivatives

Is there also an easier way to do this than the way I'm doing it? I get such long, ugly derivatives and finding the zeros is really tedious and time consuming... This is an exam review problem so I don't think the problem should take this long. Is there another approach I could use? edit: I do...