Recent content by scottie_000
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X is normally distributed and the mean of X
Have you drawn yourself a small sketch of what the curve will look like in this case? Remember that the mean is already at 12. Also, since this is a continuous distribution, you need to find the probability that X is within a range of values: P(0<=X<=12) = P(X<=12) - P(X<=0)- scottie_000
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- Forum: Calculus and Beyond Homework Help
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Solving a determinant to give it's factors
The best way to write this is using \LaTeX, but that's best learned another day. What operations for finding a determinant do you know about so far? Hint: You want to try eliminating entries in one of the rows so they become 0. What about replacing the 3rd row with (3rd+2nd+1st)?- scottie_000
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- Forum: Precalculus Mathematics Homework Help
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Is Mathematics the Language of the Universe?
Mathematics is indeed a wonderful tool to describe the world around us. And it works as a language in which we can successfully render physics. However I like to think that mathematics is universal; the way in which we communicate does not alter what we are attempting to discover. Just my...- scottie_000
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- Forum: General Discussion
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Four-velocity in a static spacetime
Anyone have any ideas? I'm sure it's very simple, but I can't think how to actually prove it- scottie_000
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- Forum: Advanced Physics Homework Help
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How Does Energy Density Change with Scale Factor in Cosmology?
You have your equation \frac{\dot\epsilon}{\epsilon} = -3(w+1)\frac{\dot a}{a} From here you can eliminate the time-dependence \frac{d\epsilon}{\epsilon} = -3(w+1)\frac{da}{a} and this is a differential equation involving just \epsilon and a you can solve by integrating both sides- scottie_000
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- Forum: Advanced Physics Homework Help
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Four-velocity in a static spacetime
Homework Statement I am given a static spacetime line element which has the property that the metric is time independent. I am asked to calculate some of the Christoffel symbols, which I have done. The question asks to show that for an observer at rest, the four-velocity is given by V^a =...- scottie_000
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- Spacetime Static
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- Forum: Advanced Physics Homework Help
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Undergrad Calculating radius from volume
^(1/3) just means cube root, so is there a button with a 3 in a square root sign?- scottie_000
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- Forum: General Math
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Projectile Equation Help: Finding Velocity for Water Thrown at 60 Degrees
Are you able to write down the equations of motion for a projectile in terms of s, u, v and t? These are the standard equations one uses to solve such problems If you can do this, then you need to be able to split the motion into horizontal and vertical components and solve from there. Let me...- scottie_000
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- Forum: Introductory Physics Homework Help
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Displacement current in Maxwell equations
Can you write down the relevant Maxwell equation, then change all derivatives in length and time to simple division by their charactersitic values?- scottie_000
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- Forum: Advanced Physics Homework Help
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Undergrad Calculating radius from volume
Or you could just answer the entire question... Is it not better to give a few hints, so that the OP will understand how to do it themselves?- scottie_000
- Post #4
- Forum: General Math
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Undergrad Calculating radius from volume
Assuming the vessel is filled with water, do you know how many litres of water is in a cubic metre? Or how many ml makes up a cubic centimetre? From there you need to be able to rearrange this equation to solve for r in terms of V- scottie_000
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- Forum: General Math
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Integrating arcsin: Solving \int \sqrt{9-x^{2}}dx with step-by-step explanation
No need to worry really. You will come across it sooner or later and it's good to know- scottie_000
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- Forum: Calculus and Beyond Homework Help
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How Do You Solve This Second-Order Linear Differential Equation?
Do you know how to solve x^2 y'' + axy' + by =0 in general? Hint: Use the substitution x = e^z- scottie_000
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- Forum: Calculus and Beyond Homework Help
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Maximizing Volume: Rectangular Box in Hemisphere | Homework Problem
Yes the answer is likely to involve R somewhere. However, your equation for the hemisphere is slightly off: can you write down the equation for a sphere of radius R in terms of x,y and z? Once you have that, it is a simple case of restricting z to be positive as you said. Also, maximizing the...- scottie_000
- Post #4
- Forum: Calculus and Beyond Homework Help