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#26 Help Me ! » particular solution differential equations » 2007-11-13 09:10:07

EPhillips1989
Replies: 1

can anyone help me find the particular solution for the following differential equation???
dy/dx=sin(2x)-ycos(x)

with y=1 and x=0

#27 Re: Help Me ! » reduced echelon form » 2007-11-10 08:35:09

ive got it this far but now am struggling to complete row echelon form is this correct so far anyone??

1   4/(a-9)           1/(a-9)
0   a^2-12a+11   a^2-12a+23
0   12a-204         a^2-15a+30

please help!!!

#28 Help Me ! » rank of a matrix » 2007-11-09 08:49:47

EPhillips1989
Replies: 1

hey can anyone tell me what a rank of a matrix is for example i have the following matrix

1  0  3  1  2
1  4  2  1  5
3  4  8  1  2

which iv put in row echelon form

1  4  2  1  5
0 -4  1  0 -3
0  0  0 -2 -7

does anyone know how to find the rank??

#29 Help Me ! » reduced echelon form » 2007-11-09 07:45:24

EPhillips1989
Replies: 2

i have this system of equations where the augmented matrix is

(a-9)   4           1        0
-20     (a+9)     3        0
24       -12       (a-6)   0

can anyone help me put this in reduced echelon form??
i dont know what to do to the matrix to get a 1 in the leading row! please help!!!

#30 Re: Help Me ! » matrices » 2007-11-09 07:07:42

is this now in reduced echelon form???

1  1  1            1
0  a  (a^2-3)  -2
0  0   2           (b-a+2)

#31 Help Me ! » Functions » 2007-11-07 23:16:45

EPhillips1989
Replies: 1

can anyone help me with this question
describe all functions f(x)=ax^2+bx+c
such that f(1)=2 and f(-1)=6

i dont really know what this question is asking for please help!!!!

#32 Help Me ! » matrices » 2007-11-07 23:14:19

EPhillips1989
Replies: 5

X+Y+Z=1
(a+1)X+Y+(a^2+a)Z=1
(a-2)X+(a-2)Y-aZ=b
can anyone find solutions of this system of linear equations
for which values of a,b the system has
1) a unique solution
2)no solutions
3)infinitely many solutions

any help with this will be much appreciated!!!

#33 Help Me ! » long divison » 2007-11-06 06:43:24

EPhillips1989
Replies: 3

hey can anyone help me divide
x^3 by x^2+4x+5

#34 Re: Help Me ! » logs » 2007-11-05 01:13:35

iv got to
i(3x+Pi/2)-log8=0

#35 Re: Help Me ! » logs » 2007-11-05 01:06:20

i got that far do you know how to find x when

3ix=log8-Pi/2i??

#36 Help Me ! » logs » 2007-11-05 00:20:21

EPhillips1989
Replies: 3

hey i was just wondering what happens when you take logs of both sides of equations like the following

e^(3ix)=8e^(-PI/2i)

what happens to the 8??? please help asap xxxxxxx

#37 Help Me ! » polar form » 2007-11-04 23:31:34

EPhillips1989
Replies: 1

hey can anyone please help me express 8i in polar form???
help will be very much appreciated

#38 Help Me ! » surjective function » 2007-11-03 09:16:08

EPhillips1989
Replies: 3

hey can anyone ive me an example of a surjective function when
Z*N->Q???

will be much appreciated if you could share your ideas thanks in advance xxx

#39 Help Me ! » exponentials » 2007-11-03 05:16:08

EPhillips1989
Replies: 1

hey does anyone know how i can solve these exponentials

2cosh^2(x)=1+cosh(2x)

2sinhxcoshx=sinh(2x)

please help!!!

#40 Help Me ! » volume of an ellipse » 2007-11-03 05:13:35

EPhillips1989
Replies: 4

does anyone know how to calculate the volume of an ellipse when it is revolved completely around the x-axis??
for example x^2+9y^2=9

does anyone know the formula???

#41 Help Me ! » length of a line » 2007-11-03 05:11:48

EPhillips1989
Replies: 2

hey does anyone know how to find the length of a curve joining to given points
for example
find the length of a curve y=4/3x^(3/2) joining the points (0,0) and (1,4/3)

does anyone know how to do this using intergration???

please help will be very much appreciated xxx

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