# Search results

1. ### Double integral and reversing order

Homework Statement http://img10.imageshack.us/img10/3390/55486934.jpg [Broken] Homework Equations This is what I was thinking: tan−1(∏x)−tan−1(x)=∫^{g(x)}_{f(x)}h(y)dy The Attempt at a Solution I don't really understand how to do this question
2. ### Matrix transformation

Homework Statement just wondering, what exactly is T2(v)=0? is it T(T(v))=0 or T(v)*T(v)=0?? Homework Equations The Attempt at a Solution
3. ### Quick ! T(A) = Tr(A)

Quick plz! T(A) = Tr(A) Homework Statement Let T : M22 define as T(A) = Tr(A). Show that T is a linear transformation and find the dimension of ker T. Homework Equations The Attempt at a Solution what is Tr(A)? is it trace(A), or rT(A) , r is a real number?
4. ### Find a basis of U, the subspace of P3

Homework Statement Find a basis of U, the subspace of P3 U = {p(x) in P3 | p(7) = 0, p(5) = 0} Homework Equations The Attempt at a Solution ax3+bx2+cx+d p(7)=343a+49b+7c+d=0 p(5)=125a+25b+5c+d=0 d=-343a-49b-7c d=-125a-25b-5c ax3+bx2+cx+{(d+d)/2} -->{(d+d)/2}=2d/2=d...
5. ### Quick diagonalize matrix (row reduce)

quick plz..diagonalize matrix (row reduce) Homework Statement http://www.math4all.in/public_html/linear%20algebra/chapter10.1.html 10.1.5 Examples: (ii) this part: ----------------------------------------------------------------------------------------- are both eigenvector for the...
6. ### Quick questionmatrix (similar~)

Homework Statement just wondering if A is similar to the reduced(or non-reduced) row echelon form of A Homework Equations The Attempt at a Solution
7. ### Quick Find a Basis

Homework Statement http://en.wikibooks.org/wiki/Linear_Algebra/Vector_Spaces_and_Linear_Systems/Solutions Problem 14 Can answer be (3,1,2)T (2,0,2)T? also, can I reduce the matrix without transpose? thanks Homework Equations The Attempt at a Solution
8. ### Subspace question

Homework Statement [PLAIN]http://img683.imageshack.us/img683/4530/unledkw.jpg [Broken] can someone please explain why it is not closed under addition??? My textbook did not explain very well, but I understand this can be zero vector and it is closed under scalar multiplication. thanks...
9. ### L'Hopital's Rule

Homework Statement lim x->0 5x(cos 9x-1)/sin 5x-5x Homework Equations The Attempt at a Solution answer is 243/25 The derivative of sin 5x-5x is always 0, dunno know how to do it...
10. ### Newton cooling law

Homework Statement An object of temperature 60oF is placed in a medium maintained at a constant temperature moF. At the end of 5 mins thetemperature of the object is 45 oF and after another 5 mins its temperature is 36 oF. Find m Homework Equations y=cekt+m The Attempt at a...
11. ### Differentiating (2x - 10 + e)^(y + 8à = e^(x - 6)

Homework Statement (2x-10+e)^(y+8)=e^(x-6) value of dy/dx at the point, (5,-9) Homework Equations The Attempt at a Solution (y+8)ln(2x-10+e)=x-6 y' ln(2x-10+e)+(y+8)(2+e)/(2x-10+e)=1 ln(2*5-10+e)=1 y'+(-9+8)(2+e)/e=1 y'-(2+e)/e=1 y'=1+(2+e)/e but the answer is (2+e)/e, I don't know...
12. ### Quick matrix question

Homework Statement the system have infintely solutions when the bottom row is 0,0,0,0, what If the bottom row of the matrix is 0,0,1,1 like X,Y,Z, 1,0,2,3 0,1,2,3 0,0,1,1 can i still say the system have infinitly solution? Homework Equations The Attempt at a Solution
13. ### Matrix problem

Homework Statement Suppose that a country is divided into three regions: Upper, Lower and Central. Each year, one-quarter of the residents of the Upper region move to the Lower region and the remaining residents stay in the Upper region. One-half of the residents of the Lower region move to...
14. ### Integration by parts (LIPET Or LIATE)

Homework Statement Can anyone tell me which one is right (LIPET or LIATE)? Also, in trig, which one come first? sin,cos or tan? thx Homework Equations The Attempt at a Solution
15. ### Antiderivative math homework help

Homework Statement \int(2x^2+1)^7 Homework Equations The Attempt at a Solution u=2x^2+1 du=4xdx u7 (1/4x)du I am stuck... I don't know what to do next...
16. ### Derivative homework

Homework Statement Can someone check my homework? http://img10.imageshack.us/img10/9686/48742895.jpg [Broken] http://img229.imageshack.us/img229/6981/52780988.jpg [Broken] http://img297.imageshack.us/img297/6955/85086758.jpg [Broken] http://img11.imageshack.us/img11/1221/86324492.jpg...
17. ### Limit of a function

Homework Statement http://img23.imageshack.us/img23/9366/95631341.jpg [Broken] Homework Equations The Attempt at a Solution If the dot (-1,3) is gone, does the limit of x->-1 exist??
18. ### Limit Need someone to check

Homework Statement http://img23.imageshack.us/img23/9366/95631341.jpg [Broken] http://img341.imageshack.us/img341/3416/37907619.jpg [Broken] lim f(x) x->1\infty I don't know how to do the first one.. ty! Homework Equations The Attempt at a Solution
19. ### Can you anyone help me to set up a ice chart for this one?

Homework Statement if the pH is 9.72 for the following 2 bases. what is the initial conc. of the bases a)LiOH b)HCN the answer for a is 10^-4.28, but i don't know how to set up an ice chart Homework Equations The Attempt at a Solution

Homework Statement The practical limit to ages that can be determined by radiocarbon dating is about 41000 yr. in a 41000 yr old sample, what percentage of the original carbon-14 remains? Homework Equations The Attempt at a Solution I don't know where to start....
21. ### Mass deflect and binding energy

Homework Statement Energy is required to separate a nucleus into its constituent nucleons. this energy is the total binding energy of the nucleus. for example, separating nitrogen-14 into nitrogen-13 and a neutron takes an energy equal to the binding energy of the neutron. use the following...
22. ### How to determine b in a conic hyperboal graph

How to determine "b" in a conic hyperboal graph Homework Statement http://img143.imageshack.us/img143/3391/91667159.jpg [Broken] (x-1)2/22 - y2/b2 =1 I can't find any good point for me to solve b..I don't know what to do.. Is there any way to solve b without using the point? Homework...
23. ### Alpha, Beta, Gamma , neutron ray, which one is harmful?

Homework Statement If you were given 4 cookies, each emitter different ray 1)Alpha, 2)Beta,3) Gamma , 4)neutron You have to make decision of the following: a)eat one of the cookies b)dispose one of the cookies at storage facility called WHIP c)put one of the cookies in your pocket...
24. ### Bohr Model (Lyman,Balmer,Paschen series)

Homework Statement Determine the wavelengths of photons given off for the 3rd line in the Lyman series , the 2nd line in the Balmer series, and the 1st line in the Paschen series. The question is weird, I don't understand what the "line" mean... "1st line in the Paschen series " Is it mean ni...
25. ### Does adding different solid affect the quilibrium?

Homework Statement CoCl4 2-+6H2O --> Co(H2O)62++4Cl-+energy If I add silver nitrate, which direction does it shift? I think it is no effect, because adding solid does not affect the equilibrium?... Am i right? Btw, what happen if i add aqueous to X gas --> Z gas + Y gas, vise verse... or gas...
26. ### Extremely Hard Physic Question (Ray diagram)

Homework Statement http://img163.imageshack.us/img163/7010/78614537.jpg [Broken] o= student The position of the teacher is (d) from the mirror. mirror is 6m a) Calculate the maximum distance(d) of the corridor from the mirror b) Trace the diagram. Draw the ray diagram to support your...