Recent content by DivisionByZro

The absolute value function is defined as: |a| = -a if a<0 |a| = a if a>=0 This is what you have to work with.

It would be helpful if you posted your code. I find your post very confusing to sort through.

:smile: :smile:

How are we supposed to answer this question if we don't even know where you are located? Cost of living is commensurate with location.

What is your question? We can't just guess.

"Please answer"? How about you show some effort first? You should have read the forums rules by now.

For online material, I cannot recommend anything else but: khanacademy.org It has complete tutorials in the form of videos on almost anything, and exercises and solutions. You can also keep track of your progress and quiz yourself. It's an amazing resource. Otherwise, in terms of books, the...

Although you did give an answer without the OP showing much effort, I must say that the above solution is very elegant!

Here's a blog entry from one of our mentors, micromass: https://www.physicsforums.com/blog.php?b=3654 Hope that helps.

Suppose you have: x \cdot a + x \cdot b = c Then you clearly can't group the a and b together. However, this is what you can do: x\cdot(a+b) = c In your case: \frac{3}{5} \cdot (cos^{2}(x) + sin^{2}(x)) = \frac{3}{5} \cdot 1

I did not say that "symmetric functions" reach their maxima/minima when all of their values are equal, I said that if the constraints are symmetric, and the function is symmetric with respect to each parameter, then there is no reason that the solution would not be symmetric as well. It's a...

Yep, that's right! If it's a minimum, then picking any other values (Ex: a=0.7, b=0.2, c=0.1) will yield something higher than 9, always. So you're done now. But notice that you could have finished this problem in your head: if a+b+c=1, and the conditions on a,b,c are symmetric (all the same)...

There's no need for anything too fancy, here's how I would tackle it: Notice that the conditions on a,b,c are symmetric, that is, consider this a problem of "optimization". Suppose I give you: Maximize x*y*z subject to x+y+z<=100, then you have a few options: 1 - Solve this problem using...

On one line you have: But on the other: Surely you meant to plug in values to "xy = xz"?

Is this the problem? \lim_{x\to\infty}\frac{(b^{x}-1)}{x(b-1)}^{\frac{1}{x}}