Stuck Definition and 836 Threads

Hello everyone I need some help in performing the following integration (not HW): \int_{0}^{\pi/4}\left(\frac{x}{x\sin x + \cos x}\right)^{2}dx I tried integration by parts, but it leads nowhere. Any suggestions would be appreciated. Thanks Vivek PS--Mathematica gives the answer as...

I'm trying to do the following: int (3x^3 + 4x)/(x^2+1)^2 dx I let u = x^2+1 and I eventually get: int 3(u-1)+4/u^2 du/2 When I further break this down, I get: 1/2 int 3u^-1 -u^-2 du am I on the right track? When I integrate this, I'm thinking that I have to be doing something...

here is the question: A race car driver sets out on a 100-kilometer race. At the quarter-way marker, her pit crew radios that she has averaged only 60 km/hr. How fast must she drive over the remaining distance in order to average 100 km/hr for the entire race? please help me out, I have...

Homework Statement Homework Equations Show that the equation \frac{2}{x+1}+\frac{1}{x+2} = \frac{1}{2} can be written as x^{2} + x - 4 = 0 The Attempt at a Solution mulitply the fractions on the LHS numerators by opposite denominators and multiply denominators togethter...

Homework Statement Let e_i = (0,0,\ldots, 1, 0 , \ldots) be the basis vectors of the Hilbert space \ell_2^\infty. Let U and V be the closed vector subspaces generated by \{ e_{2k-1}|k \geq 1 \} and \{ e_{2k-1} + (1/k)e_{2k} | k \geq 1 \}]. Show U \oplus V dense in \ell_2^\infty I am...

If a first pump is used for 2.2 hours and a second pump is used used for 2.7 hours,32m cube can be removed from a waste water holding tank. If the first pump is used for 1.4 hours and the second pump used for 2.5 hours,24m cube can be removed. How much can each pump remove in 1 hour ?. What is...

I was downloading a new OS onto my Titanium the other day and after it downloaded about 25%, it gave me some error and canceled downloading. Now, my Ti-89 is stuck in a "Waiting to receive..." screen. Left+Right+2nd+On doesn't work, and neither does taking out the batteries and putting them back...

I think it's safe enough to say everyone sometimes gets stuck on a new concept or a problem. When this happens, how do you react? Do you just move on, or insist? Do you get frustrated or remain calm all throughout? I for one get very uncomfortable (almost to the point of being tormented), get a...

Homework Statement The ionisation energy of Li is 5.39eV and the electron affinity of F is 3.40eV. Give a lower bound for the modulus of the crystallisation energy of Li+F- Homework Equations Not entirely sure of the equation to use, but have this one in my notes: U = -...

OK, I have this complex number equation: 5\,V\,=\,\left[\left(j2\,+\,1\right)\,\left(1000\,-\,j10000\right)\,+\,\left(200\,+\,j2000\right)\right]\,i_L Now I try to solve for i_L: i_L\,=\,\frac{5\,V}{\left(j2\,+\,1\right)\,\left(1000\,-\,j10000\right)\,+\,\left(200\,+\,j2000\right)}...

Hoping someone can help me here quickly. Trying to get this one question. a perfect gas is compressed adiabatically from 100 kPa and 17C to a final pressure of 500 kPa and final temp of 77C. The work done during the compression is 45 kJ/kg. Calculate the values of gamma, Cv, R and the...

1. The problem Find the definite integral. \int \frac {t^2 - 3}{-t^3 + 9t + 1} dt2. The attempt at a solution The answer is the book made it seem like the rule \int \frac {du}{u} = ln|u| + C was used. Here's what I got: u = -t^3 + 9t + 1 du = -3t^2 + 9\;dt -\frac{1}{3}du = t^2 + 9\;dt...

Homework Statement \int\frac{1}{t^4+16}\,dt Homework Equations Various integration formulas. I am pretty stuck.The Attempt at a Solution I have tried various substitutions, with no success. I tried t^2 = 4u, hoping to get it into the form 1/(u^2+1) so I could use the arctan formula, but then...

Hello. I am stuck with linear difference equations and i would like some help. I was given that y(k) = y(k)homogeneous + y(k)particular and i am asked to solve the linear equation: y(k+1) + y(k) = k with initial condition y(0) = 0 the homogeneous solution is y(k+1) + y(k) = 0 n + 1 =...

Homework Statement Homework Equations As in the image above The Attempt at a Solution I had a go but i rubbed it off the sheet. Can someone take me through this step by step on how to solve it Thanks

Homework Statement Find \int \frac{x^{2}+3x+7}{\sqrt{x}}dx Homework Equations The Attempt at a Solution I am reviewing for a test on tuesday. I can't see a good algebraic method to solve this using the fact that \int f(g(x))g'(x)dx=F(g(x))+C so I am starting to think it...

Homework Statement Suppose that you wish to fabricate a uniform wire out of 0.900 g of copper. If the wire is to have a resistance R = 0.700 ohm, and if all of the copper is to be used. (a) What will be the length of the wire? M Homework Equations R = pL/A R = .700 ohm and p =...

stuck on Change of Phase problem How much ice at 0 degrees Celsius must be mixed with 50.0 g of water at 75.0 degrees Celsius to give a final water water temp. of 20 degrees Celsius? ive been trying to work this out for the past hour, but having trouble...any help would be appreciated.

1. Suppose a constant potential energy,Vo, independent of x and t is added to a particle's potential energy. Show that this adds a time-dependent phase factor, e^{-iV_ot/\hbar}Right now I'm completely lost. Here's what I think so far: 2. i\hbar\frac{d\Psi}{dt} =...

Homework Statement You don't need it verbatim. I'm just trying to solve for the eigenstates and eigenvalues of the Hamiltonian for a one-dimensional infinite square well, with a particle of mass M inside. I'm embarrassed to say it, but the question is throwing me off because the infinite well...

Info A model train has an electric motor to drive it. The current though the motor is controlled by a rheostat and when it is moving slowly the current is 0.5A and the voltage is 5V. Data Total Power = 6W Power Developed By Motor = 2.5W Power Absorbed By Controller = 3.5W Total Voltage...

Homework Statement a body mass of 5kg starts off from rest and is acted upon a force of 5N over a distance of 2m. if there is no frictional forces make use of the principle of the conservation of energy to determinei ts final speed Homework Equations above is all i have. The...

I am stuck on a problem that is probably was easier than I am making it out to be, but I am wondering if anyone can help me out. The question is: How many feet are in a light-second. I would appreciate some help with this problem, 'cuz I have attempted this problem many times, but still am...

I actually managed to get my Jeep stuck last night ... in a parking lot, no less. That's the first time I've ever managed to get stuck. It was hard to gauge the depth of the snow in an unplowed lot, and I wound up a little too close to the building where the snow was a little deeper. That...

Homework Statement "An 80.0 kg skydiver (initially at rest) jumps out or an airplane at an altitude of 1000.0 m and opens the parachute at some altitude. Assuming that the totalretarding force on the skydiver is constant at 50.0 N with the parachute closed and the constant at 3600.0 N with...

Homework Statement How many wavelengths of radiation emitted by a 60 Hz electrical transmission line would it take to span the North American continent (a distance approximation 5.0*10^3 km). f=60Hz d=5.0*0^3 km=5.0*10^6 m Homework Equations v=fλ Δd=vΔt The Attempt at a...

Just stuck on a few problems on my homework, any help? 1. How many different sets of quantum numbers are possible for an electron for which: a) n=1 b) n=2 c)n=3 d)n=4 e)n=5 2. For a hydrogen atom in its ground state, use the Bohr model to compute: a) the orbital speed of the...

I've been trying to invent a formula for solving certain sides and angels on objects... and I've tried many different ways to get the formula for it, I think I might have it, but there's this one line I can't figure out how to solve... help would be appreciated. -4 ln | (csc53 + cot53) = -3...

a car pulling 20,000pounds accelerate uniformly from a rest to a speed of 40 miles/hour in 12 seconds (a) find the distance (infeet AND miles) that the car travels during this time (b) find the constant acceleration in ft/s^2 of the car part a i get 480 feet is this correct i then...

Hello, I am an engineering student doing my first real engineering project with a group of other engineering students. To give a background of my issue, I am charged with the task of designing a system which is able to detect when a rotating shaft spins too fast and send an appropriate...

I have done most of a question except for the most important part, putting in the boundary conditions, I can't really interpret them. The question is: I managed to solve this, with -c^2 as a separation constant, and I got: T(x,t) = X(x)F(t) = (A_{1} \cos{\frac{cx}{\sqrt{\kappa}}} + A_{2}...

I have to prove Liebniz's Rule by induction. So the p(1) is just the product rule. I am assuming the p(n) is true. Now when I expand the series for p(n+1) I am stuck. I think I need to collect the terms in the n+1 expansion and show that they are just one term expansion more than the n...

I'm brushing up on the physics, and am teaching myself from University Physics w/ Modern Physics 10th Edition (I got 11th off eBay with the solution manual, it should come in about a week). I haven't had too much trouble with the problems up until the section about the dynamics of rotational...

I'm in the middle of solving \int\sqrt{x^2+9}dx and I got it into the form of 3\int\sec^3\theta d\theta, and I'm pulling a blank. Where does one begin? I could integrate by parts, setting u=sec(theta) and dv=sec^2(theta), but it's not getting me very far. Any suggestions?

Hello everyone. I'm stuck on this problem and not sure how to apply the Unique factorization therem also called (Fundamental Theorem of Arithmetic). Heres the problem: http://suprfile.com/src/1/45ym0fx/lastscan.jpg The back of the book gives a pretty big hint which is the following...

Help! Stuck on problem for 2 days. A 75.0 kg stunt man jumps from a balcony and falls 26.0 m before colliding with a pile of mattresses. If the mattresses are compressed 0.950 m before he is brought to rest, what is the average force exerted by the mattresses on the stuntman? N I am really...

I've been going over the book and everything was going well until I got to this question: \frac{1} {2 + \sqrt{4 - x^2}} = \frac{2 - \sqrt{4 - x^2}} {x^2} Tried with partial fractions but that does not work. I also tried to split the fraction but I don't know how to get the x^2 at the...

I'm supposed to integrate the following expression, and supposedly there is a very simple way to do so. Maple comes up with something rediculous, so I'd appreciate any input. Sorry about the short hand, don't know how to make everything pretty on here: Integral[(e^ax)cos^2(2bx)dx] where a and...

Suppose x is a discrete, binomial random variable Calculate P(x > 2), given trails n = 8, success probability p = 0.3 and given trails n = 6, success probability p = 0.1

Hi all, If a square matrix A of dimension n*n is a nilpotent matrix,i.e, A^k=0 for k>=m iff A has eigenvalues 0 with multiplicity n and index m or less. I did prove by induction if A^k=0 then all the eigenvalues are zero. I'm lost when I want to prove the oppesite, i.e, if all eigenvalues are...

Hi everyone Here are two improper integrals and I have to find the values of p for which they are convergent 1. \int_{0}^{\infty} \frac{1-e^{-x}}{x^{p}}dx 2. \int_{0}^{\infty} \frac{t^{p-1}}{1+t} dt As I do not know the answers and am somewhat stuck with the reasoning, I...

Probability Problem- I am still stuck ! Hi i need help on the following question: In a teashop 70% of customers order tea with milk, 20% tea with lemon and 10% with neither. of those taking tea with milk 3/5 take sugar, of those taking tea with lemon 1/4 take sugar, and of those taking tea...

A moving truck strikes a parked car. During the collision the cars stick together and slide to a stop together. The moving truck has a total mass of 2747 kg (including driver), and the parked car has a total mass of 1068.0 kg. If the cars slide 67.5 m before coming to rest, how fast was the...

Hi all. I have a Casio fx-85MS scientific calculator but forgot how to work it. I need to do calculations like 2000/(1+0.08) to the power of 9. Its a formula for working out the value of money in x amount of years at 8% discount factor. I can't rememer how to get the power of function on the...

~~~Now I'm Really Stuck~~~ The supersonic aircraft Concorde has a length of 61.2 m when sitting on the ground on a typical day when the temperature is 16.0 °C. The Concorde is primarily made of aluminum. In flight at twice the speed of sound, friction with the air warms the Concorde's skin and...

a 10g bullet is fired into a 10kg wood block that is at rest on a wood table. The block, with the bullet embedded, slides 5.0cm across the table. What was the speed of the bullet? So my question is how do I get started, this problem has had me stuck for awhile. Thanks

Prove that Venus’s orbit is .72 times the size of Earth's orbit. I’m told that Venus’s greatest elongation is 47 degrees.

hey hey.. I need help again. I can't believe I've forgotten my simple algebra. Anyway.. is there a way to solve the following without using the quadratic equation? 0 = (22)t + 1/2(-9.8)t^2 I'm tryin to isolate t, so i can solve for time. I know you can factor it out as...

If anyone's got any hints or directions as to how to go about solving this problem, PLEASE help! An explorer is caught in a whiteout (in which the snowfall is so thick that the ground cannot be distinguished from the sky) while returning to base camp. He was supposed to travel due north for...

I'm stuck. Here's the question, Q: The upper and lower conducting plates of a large parallel-plate capacitor are separated by a distance d and maintained at potentials V_0 and 0 , respectively. A dielectric slab of dielectric constant 6.0 and uniform thickness 0.8d is placed over the...