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visits member for 1 year, 6 months
seen May 19 at 7:47

Apr
20
comment Distance between the two points $P$ and $Q$
Yes, they are. Here is the general formula: $d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$
Apr
3
comment Volume by cross-section of a donut
Guys, I am sorry for not correct answer at first.. I am at work and distracted a lot. Everything is correct now.
Apr
3
comment Volume by cross-section of a donut
You must have an error in your calculations, you can post them and we'll check or I can write my owns.
Apr
2
comment How to find the least positive root?
WolframAlpha might be a handy tool too. You can get pretty accurate approximations of roots by just typing your equation.
Apr
1
comment How to find $\frac{d^2x}{dy^2}$
I had to tilt my head to read your answer :D
Mar
29
comment Introductory Level Books for Graph Theory
math.stackexchange.com/questions/27480/…
Mar
29
comment Probability Dice Problem
Your solution is not quite right. I don't even understand what it tries to calculate.
Mar
28
comment Solving $\sqrt{x}-2\sqrt[4]{x}-8 = 0$
Hint: Denote $u=\sqrt[4]{x}$, you will get $\sqrt{x}=u^2$.
Mar
27
comment How to count angle between vector and horizontally oriented vector?
That plot is not quite right, look at the scales of x and y axises. If you want to see the actual angle you must have the same scale on both of them. Imagine $AB=4mm$ and $BC=136mm$, do you see how big is angle $CAB$?
Mar
27
comment How to count angle between vector and horizontally oriented vector?
How did you get numerator 2, it should be 1? Double check your code in that part.
Mar
27
comment How to count angle between vector and horizontally oriented vector?
I am sure you miss the arccosine, check that too. And make sure you are calculating length with the right formula: len(v)=sqrt(v.x*v.x + v.y*v.y).
Mar
26
comment How to get the minimum angle between two crossing lines?
Right, that's absolute value.
Mar
26
comment How to get the minimum angle between two crossing lines?
Hmm, I think I made an error there. Let me review it.
Mar
25
comment Find$\frac{dz}{dx} \text{for} \ z = \frac{xy}{x^2+ y^2}$
I also find your answer right. Maybe you misanderstood the question and it asks for something else?
Mar
24
comment How to tackle questions involving count?
In case of real problems(not math exercises), you can use any programming or scripting language to write basic programs.
Mar
24
comment LOVES+LIVE=THERE. How many “loves” are “there”?
You can't take LOVES=89990, all the digits must be different.
Mar
23
comment Combinatorics Question, drawing from a pot
I read the question again and it seems d) is impossible, if we interpret it like c). So yes, you are right.
Mar
23
comment Combinatorics Question, drawing from a pot
I've edited the answer. d) and e) are the same. It is possible to use combinatorics, but you'll have to deal with conditional probabilities and probably end up with some sum, but you will not get a nice formula.
Mar
22
comment Find the radius in dependency of a (the side length)
The new picture is still not enough to correct your problem. Can you tell what exactly your professor told you?
Mar
22
comment Find the radius in dependency of a (the side length)
When I said not dependent I meant $r$ cannot be expressed in terms of $a$. You can make $a$ as big as you want without affecting $r$.