# Search results

1. ### Bifocul Optics Problem Help Please

Homework Statement A woman is wearing bifocals that have one-half of the lens with a power of -1.2 D and the other with a power of 1.8 D. A lens provides her with a far point set at infinity and other will give her a near point of 25 cm. Where are her near point and far point WITHOUT her...
2. ### T-shirt problem!

okay, so I am making an astrophysics/physics shirt and I want it to be really funny. anyone have any ideas?
3. ### Taking Electrodynamics this semester

I am taking Electrodynamics this semester and we are doing the course with the aid of "david griffith's Intro to electrodynamics" there has been alot of word that the course is extremely difficult... can anyone tell me ways to prepare for it?

Hello, I am a undergraduate Physics student and I heard that if you pursue a graduate degree in Physics for grad school (not undergraduate) the department pays your tuition for you? Is this true? I have 5 friends that they have finished undergraduate physics (payed their OWN tuition) but...
5. ### The Geometry of Maps (Help)

Homework Statement Let D* = [0,1] x [0,1] and define T on D* by T(x*,y*) = (x*y*, x*). Determine the image set D. Is T one-to-one? Homework Equations The Attempt at a Solution Okay... So I know it is not one to one, if you take out the point (x=0) then it is one-to-one, so you...
6. ### Vector Calculus Question (I don't understand)

Homework Statement Let D* = [0,1]x[0,1] and define T on D* by T(u,v)=(-u^2+4u, v). Find the image D. Is T one-to one Homework Equations The Attempt at a Solution I have no idea... I don't know how to do it. The solution is [0,3] x [0,1]... yes it is one to one. am I supposed...
7. ### Absolute Max/Min

Can anyone tell me the general procedure in doing the following procedure? f(x,y)=xy^2 with domain x^2+y^2\leq4 Find it's absolute max & absolute min. Okay, here is my thought procedure, tell me what I can fix. So I would basically say, find the partial derivatives with respect to x and y...
8. ### Differential Equations WTF?

Okay, so I was sitting in my room wondering about the differential operator D. Like for example, solving the equation y\prime\prime+5y\prime+4y=0 introduce D=\frac{d}{dx} (D^2+5D+4)y=0 so you can solve it by doing D=-4, D=-1 e^-^4^x+e^-^x is the solution But how the hell do you solve...
9. ### Syl & Der

Me and my friend Syl consistently talk about Special Relativity and it's effects in nature when electrodynamic bodies move at relativistic speeds. I wanna make a discussion. What is Special Relativity? How does it work? How much do we understand?

11. ### Double Integral

\int\int(yx^2-2xy^2)dydx limits for the first are 0 \longrightarrow 3 limits for the second are -2 \longrightarrow 0 solve! help
12. ### Differential Equation (3)

Solve the Differential Equation 2yy\prime\prime+2xy\prime=0 set p=y\prime, and then it becomes case 1 in the textbook Can someone please help me solve this? It's a night mare
13. ### Differential Equations (2)

I'm having trouble setting up this solution can anyone give me a hint, or set it up, so I can see if what i'm doing is right? xy\prime=y=e^x^y using the substitution u\equiv(xy)
14. ### Differential Equations

Solve the following differential equation y\prime=\cos(x+y) Here introduce the new variable: x+y\equiv{u} Please show steps, or else I won't understand this
15. ### Riemann Zeta Function Z(z)

I was wondering how do you calculate the Riemann value, of a Riemann Zeta Function, for example the riemann zeta function for n = 0, is -1/2, which envolves a bernoulli number (what is a bernoulli number and what roll does it play in the Riemann Zeta Function), can anyone explain that to me...