Homework Statement
Room temperature is 200C and relative humidity is 60%. what is the absolute moisture
Homework Equations
Vapor pressure at 200C=17.5[atm]
PV=nRT
Molecular weight of water=18[gr/mol]
The Attempt at a Solution
The vapor pressure at 200C:
$$\frac{x}{17.5}=0.6\rightarrow...
Question: Considering the effect of an Earth sized plaent transiting a star, and blocking its light. How big will the change in ABSOLUTE birghtness be for different stellar classs O and A, if we subtract off this blocked light.
telescopes can detect very small changes in brightness...
Homework Statement
Max/min of f(x, y) = 1/x + 1/y
Constraint 1/x^2 + 1/y^2 = 1
The Attempt at a Solution
This was a question on my midterm exam and I am just wondering what the right answer would be.
With lagrange multipliers, I got two candidate points (sqrt (2), sqrt (2)) and (-(sqrt...
Question:
True or False If x^2<4 then |x|<=2
My solution:
I get -2<x<2 when I solve the problem so it should be false. Yet the text says its true? Is this a mistake? If |x| is equal to 2 then it should be a closed interval, not an open interval which seems to be correct to me.
I'm working on a ODE with initial conditions y(2)=4 and y'(2)=1/3. I solved it to be y=\frac{c_1}{|x-6|^8} + c_2|x-6|^{\frac{2}{3}}. How do I apply the second initial condition? I'm stuck at taking the derivative.
Homework Statement
Use technique of completing squares to Show that this function has an absolute minimum.
f(x, y) = x^2 + y^2 − 2x + 4y + 1
Homework Equations
Not entirely sure how completing the squares will indicate an absolute minimum.Is there some additional reasoning required?
The...
Homework Statement
What is the difference between the absolute thermodynamic temperature scale and the practical temperature scale: ITS-90?
Homework EquationsThe Attempt at a Solution
Is this mathematical concept EVER used in real life or "higher" levels of math?
I just find it to be a practically useless thing. It's like some guys sat around and invented this math concept just for the sake of it. Or, am I wrong?
I lost a mark for integrating \frac{1}{x} to ln(x) instead of ln\left| x \right|. Since the derivative of ln(x) is \frac{1}{x} not \frac{1}{\left| x \right|} why is this the case?
Homework Statement
from -lnIxI to lnI x^-1I , I try to go from -lnIxI to lnI x^-1I by using some properties.
Homework Equations
- lnIxI
The Attempt at a Solution
First I write the -lnIxI as -1*lnIxI and then I use -1 as an exponent to absolute value of x in the natural log that is
ln (...
Homework Statement
##|x^2-2| \leq 1##
Find ##x##
The Attempt at a Solution
##x^2-2\leq 1##
##x \leq \sqrt{3}##
and
##-(x^2-2)\leq 1##
##-x^2+2 \leq 1##
##x \geq 1##
Therefore the solution is ##1 \leq x \leq \sqrt{3}##
However the book gives another solution which is ##-1 \leq x \leq...
1. Determine the relative and absolute uncertainties of R-2 if R is measured to be 4.5 ± 0.005 m
2. The attempt at a solution
So according to what I know so far, multiplication and division of uncertainties requires the addition of relative uncertainties...
First I tried to get the...
How to input absolute values in FORTRAN77?
This was the code I used
READ *,H
PRINT *,H
The input I gave was 0.01
But the output I got was 0.00999999978.
On the surface of a unit sphere two cars are on the equator moving north with velocity v. Their initial separation on the equator is d. I've used the equation of geodesic deviation...
I did this question two ways, each of which yielded a different answer. I'll post method one first.
$$\left| (2|x-3|-5|x+4|) \right|$$
Sign changes occur when $x<-4$, $-4<x<3$, and $x>3$
If $x<-4$, then $|3x+26|>4$, and so $x>-22/3$ and $x<-10$. Clearly since $x$ much be less than $-4$, only...
Show that if $y_0\ne 0$ and $|y-y_0|<\min\left(\dfrac{|y_0|}{2},\dfrac{\varepsilon|y_0|^2}{2}\right)$, then $y_0\ne 0$ and $\left|\dfrac{1}{y}-\dfrac{1}{y_0}\right|<\varepsilon.$
1) True or Fale?
|a-b| \geq ||a|-|b||
My solution: I broke this up into 4 different cases. 1. a> 0 b>0 2. a<0 b<0 and so on...
For each case, I ended up with a more simplified version of the inequality. For instance, in case 1 where I used a<0 and b<0, I ended up with the simplified statement...
\d{}{x}\frac{1}{\sqrt{x}} by the definition of the derivative.
$$\lim_{{h}\to{0}}\frac{\frac{1}{\sqrt{x+h}}-\frac{1}{\sqrt{x}}}{h}=\lim_{{h}\to{0}}\frac{\sqrt{x}-\sqrt{x+h}}{h\sqrt{x^2+2xh}}=\lim_{{h}\to{0}}\frac{x-(x+h)}{h\sqrt{x^2+2xh}\left(\sqrt{x}+\sqrt{x+h}\right)}$$
Setting $h=0$...
Homework Statement
y = 1-abs(x) / abs(1-x)
The Attempt at a Solution
For x < 0, abs(x) = -x
y = (1+x) / -(1-x)
= -(1+x)/(1-x)
I stopped here because this is the part I got wrong. For x < 0, my solutions manual got (1+x) / (1-x).
What did I do wrong?
I feel like I'm asking the weirdest questions that most people don't ask, but here it is.
Suppose we have this integral (I made it up):
$$\int \sqrt{x^4+2x^3+x^2}$$
Now, I feel most people would say the answer is simply, $\frac{1}{3}x^3+\frac{1}{2}x^2+C$. But technically, that is only true...
Hi, while solving differential equations problems we have to sometimes use absolute value while
taking an integral of which 1 over a function. But in some problems I understand that we do not
have to use absolute value sign for example if the function related with atom number which can...
1.
What if absolute convergence test gives the result of 'inconclusive' for a given power series?
We need to use other tests to check convergence/divergence of the powerr series but the matter is even if comparison or integral test confirms the convergence of the power series, we don't know...
Homework Statement
In integration, we are allowed to use identities such as sinx = \sqrt{1-cos^2x}. Why does that work, and why doesn't make a difference in integration? Graphing \sqrt{1-cos^2x} is only equal to sinx on certain intervals such as(0, \pi) and (2\pi, 3\pi). More correctly...
In integration, we are allowed to use identities such as sinx = \sqrt{1-cos^2x}. Why does that work, and why doesn't make a difference in integration? Graphing \sqrt{1-cos^2x} is only equal to sinx on certain intervals such as (0, \pi) and (2\pi, 3\pi). More correctly, shouldn't we use the...
To find E |X| of a cauchy random variable, I need to integrate
\int_{-\infty}^{\infty}\frac1{\pi}\frac{|x|}{1+x^2}dx .
From the definition of absolute value, we have
\int_{-\infty}^0\frac1{\pi}\frac{-x}{1+x^2}dx + \int_0^{\infty}\frac1{\pi}\frac{x}{1+x^2}dx (I think).
But, the very next...
Hey guys, I'd appreciate some help for this problem set I'm working on currently
The u-substitution for the first one is somewhat tricky. I ended up getting 1/40(u)^5/2 - 2 (u) ^3/2 +C, which I'm not too sure about. I took u from radical 3+2x^4.
For the second question, I split the integral...
Problem:
y = ln|sec(x) + tan(x)|
Attempted Solution: See Attachment
I was hoping someone could identify my error and possibly write it out for me. At first I thought my steps were correct and everything was in order. However, when I checked my answer on WolframAlpha it gave me a slightly...
Hello,
I am trying to find the absolute min-max of the function:
\[f(x,y)=xy^{2}\]
over the set:
\[D=x^{2}+y^{2}\leq 1, y\geq 0, x\geq 0\]
Usually, when I have a problem where D is a rectangle, I check every line out of 4 for min-max. If D is a triangle, the same. If D is a circle, I...
I'm running a simulation on a gas mixture that spits out its Specific Heat in a number of different units.
The values for Specific Heat in Btu/lbmolF vs Btu/lbmolR are the same, which confuses me at first glance.
I sort of remember in Thermo not having to worry about Btu/lbmolF vs...
I'm trying to find the appropriate formula (and abstractions to plug into it as necessary) to work out the absolute magnitude (from which I can dervive an apparent magnitude) of a solar body.
I've found a lot of formula which relative absolute and apparent magnitude, but trying to find how to...
Can someone explain to me why |2-x| would have a horizontal translation to the right? When I've always been taught that anytime you see a [+] it will translate to the left. The graph would be a regular |x| graph but it is shift 2 spots to the right. Thanks to anyone for help
>According to http://www.chemguide.co.uk/physical/redoxeqia/introduction.html each electrode has an absolute electrode potential which is the difference between the positiveness and negativeness. So if we had a Zn plate in water and it has a negative charge of -5 on the metal. Would the absolute...
Homework Statement
I have to find current absolute acceleration in attached picture in points 1,2,3,4 and draw vectors.
The picture is rotating pendulum. The rest data show attached picture:
Homework Equations
aabs = arel + au + acor
acor=2*angular velocity X vrel
The Attempt at a...
☺'s question at Yahoo! Answers: a definite integral whose integrand has an absolute value factor.
Here is the question:
I have posted a link there to this thread so the OP can view my work.
"Geometric absolute"
If exist a function called absolute that ensures that the result have always the posite sign, so, exist some function that ensures that the sign of the result is always ×?
##f(x) = x##
##f(\frac{1}{x}) = x##
Homework Statement
I have a simple problem with roots and absolute values. When is the root of a number both negative and positive? Is only the equation of a number say f(x) = √x both the negative root and the positive root?
Homework Equations
If a = 1; b = -2, och x = a2√(ab-b2+2)
Why is x...
The Finite difference scheme:
\begin{equation} y_{n+3}-y_{n+1}= \frac {h}{3}(f_{n}-2f_{n+1}+7f_{n+2})
\end{equation}
Deduce that the scheme is convergent and find its interval of absolute stability(if any)
=> the first characteristic polynomial is then
\begin{equation} ρ(r)= r^3 -r...
Hello folks! I have just come from a night at the pub with fellow students of life where over many a pint several mysteries of the universe were discussed. One of my friends asked me a question concerning special relativity that initially took me by surprise and which has me wondering about the...
Could there be an absolute 'state of reference' somewhere in the universe, perhaps at the location of the original center? If so, would it have to hold the same frame of reference in each dimension, including time? How would it do so?
Looking at the Hafele-Keating Experiment in particular...
While Planck time is usually regarded as the shortest unit of time, isn't the shortest unit of time that can exist is the time it took to go from absolute time, the big bang, to everything after that i.e. local time? Did local time exist at the instant of the Big Bang?
Important: All Logs are base 10 and not the natural log.
Homework Statement
This question is from Foundations of Astrophysics from chapter 19
Suppose the Milky Way consisted of 2.7x10^11 stars, each of solar luminosity MB=4.7. What would be the absolute magnitude of the whole galaxy?
To...
Homework Statement
Prove that for every two real numbers x and y
##|x+y| \leq |x| + |y| ##Homework Equations
The Attempt at a Solution
There are three cases. The easiest ones is when they are both positive and negative.
The third one I have problems with.
The numbers have different sign. Say...
I just performed a lab in my physics class, and there are a few conceptual questions that I am having trouble with. The lab was simple. We took a constant volume sphere made of Stainless steel and filled with air. We changed the temperature of the water it was into record the corresponding...
In the spirit of this forum I should first announce:
-generally, I have no idea what I'm talking about but look for you folks to enlighten me.
Question:
If I am traveling at a significant fraction of the speed of light and I wish to know my current absolute velocity can I use the speed of...
I am looking for information to assist me in designing a model or program to draw a straight line bisecting the universe. Ok maybe just the Milky Way galaxy. I would like to view this line from various points 1. as viewed from a point on Earth (possibly one of the poles) 2. as viewed from a...